Camera

ABSTRACT

A camera using an image blur prevention device including exposure time calculating apparatus which calculates a first exposure time from at least photometry data, sensitivity data of a recording medium and brightness of a photographic lens, a strobe lighting designating apparatus to forcibly light a strobe when the first exposure time calculated by the exposure time calculating apparatus is longer than a predetermined value, shutter closing time setting apparatus which forcibly fixes the first exposure time calculated by the exposure time calculating apparatus at a predetermined exposure closing time Tb or Td regardless of a calculated result of the exposure time calculating means when the first exposure time is longer than the second exposure time and changing apparatus which changes a combination of the first exposure time and the second exposure time dependently on whether or not the image blur prevention device is to be used for photographing, whereby the camera is capable of taking a photograph on which not only a main object but also a background is exposed adequately by making most of the image blur prevention device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a camera which uses an image blurprevention apparatus such as an image blur correction apparatus.

2. Related Background Art

Cameras are currently automated in all important photographingoperations such an exposure determining operation and a focusingoperation, thereby allowing even unskilled persons to make photographingerrors at remarkably low possibilities.

In the recent years where researches have been made for systems whichprevent hand vibrations from being applied to cameras, there remains fewcauses to induce photographers to erroneous photographing.

Brief description will be made of the system which prevents the handvibration from being applied to a camera.

The hand vibration which is caused at a photographing time usually has afrequency of 1 Hz to 10 Hz, and a basic concept for enabling to obtain aphotograph free from image blur regardless of the hand vibration lies indetecting a camera vibration caused by the hand vibration and displacinga correction lens in accordance with a detected value of the cameravibration. In order to obtain the photograph free from the image blurregardless of the hand vibration, it is therefore necessary first toaccurately detect the camera vibration and secondly to correct avariation of an optical axis caused by the hand vibration.

The vibration (camera vibration) can be detected in principle with acamera equipped with a vibration detection apparatus comprising avibration sensor which detects an acceleration, an angular acceleration,an angular velocity and an angular displacement, and a calculationdevice which adequately calculates outputs of the vibration sensor inorder to correct the camera vibration. The image blur is suppressed bydriving correction means which makes a photographing optical axiseccentric on the basis of detection data.

FIG. 28 is a perspective view showing an appearance of a compact camerahaving a vibration prevention system which has functions to correct avertical vibration indicated by an arrow 42 p and a horizontal vibrationindicated by an arrow 42 y relative to an optical axis 41.

A camera body 43 comprises a release button 43 a, a mode dial (includinga main switch) 43 b, a retractable strobe 43 c and a finder window 43 d.

An internal configuration of the camera shown in FIG. 28 is illustratedin FIG. 29, wherein a reference numeral 44 denotes a camera body, areference numeral 51 denotes correction means, a reference numeral 52denotes a correction lens, a reference numeral 53 denotes a supportframe which corrects the vibrations in directions indicated by thearrows 42 p and 42 y shown in FIG. 28 by freely driving the correctionlens 52 in directions indicated by arrows 58 p and 58 y in FIG. 29 andwill be described later in detail. Reference numerals 45 p and 45 ydenote vibration detection devices such as an accelerometer and anangular velocity sensor which detect vibrations around arrows 46 p and46 y respectively.

Outputs from the vibration detection devices 45 p and 45 y are convertedby calculation devices 47 p and 47 y described later into driving targetvalues for the correction means 51 and input into a coil of thecorrection means 51 for correcting the vibrations. In addition, areference numeral 54 denotes a base plate, reference numeral 56 p and 56y denote permanent magnets, and reference numeral 510 p and 510 y denotecoils.

FIG. 30 is a block diagram illustrating in detail a configuration of theabove described calculation device 47 p and 47 y, which are similarlyconfigurated, therefore explanation will be made by using only thecalculation device 47 p.

The calculation device 47 p comprises a DC cut filter 48 p, a low passfilter 49 p, and analog/digital converter circuit (hereinafter referredto as an A/D converter) 410 p and a driving device 419 p which areenclosed by a chain line, and a camera microcomputer 411 which isenclosed by a dashed line. The camera microcomputer 411 comprises amemory circuit 412 p, a differential circuit 413 p, a DC cut filter 414p, an integral circuit 415 p, a memory circuit 416 p, a differentialcircuit 417 p and a PWM duty changing circuit 418 p.

A vibrating gyroscope which detects a vibration angular velocity of thecamera is used as the vibration detection device 45 p, and the vibratinggyroscope is driven when a camera main switch is turned on and startsdetecting the vibration angular velocity applied to the camera.

The DC cut off filter 48 p configured by an analog circuit cuts off DCbias components which are overlapped with an output signal from thevibration detection device 45 p. The DC cut filter 48 p is configured byhaving a characteristic to cut off signal components having frequenciesnot higher than 0.1 Hz so that these components do not influence on thehand vibration having the frequencies from 1 to 10 Hz applied to thecamera. However, the characteristic which cuts off the signal componentshaving frequencies not higher than 0.1 Hz poses a problem that itrequires about 10 seconds to cut off the DC components completely aftera vibration signal is inputted from the vibration detection device 45 p.Accordingly, a time constant of the DC cut filter 48 p is shortened (toobtain a characteristic to cut off signal components having frequencies,for example, not higher than 10 Hz) for 0.1 second, for example, afterthe camera main switch is turned on so that the DC components are cutoff in a short time of about 0.1 second and then the time constant isprolonged (to obtain a characteristic to cut off signal componentshaving frequencies not higher than 0.1 Hz) so that a vibration angularvelocity signal is not degraded by the DC cut filter 48 p.

The low pass filter 49 p which is configured by an analog circuitamplifies an output signal from the DC cut filter 48 p adequately inaccordance with resolution of the A/D converter circuit 410 p and cutsoff high-frequency noise overlapped with the vibration angle velocitysignal from the output signal from the DC cut filter 48 p. The noise iscut off from the vibration angular velocity signal so that it will notcause the A/D converter circuit 410 p to erroneously sample or read at astep to input the vibration angular velocity signal into the cameramicrocomputer 411. Furthermore, an output signal from the low passfilter 49 p is sampled by the A/D converter circuit 410 p and input intothe camera microcomputer 411.

Though the DC bias components have been cut off by the DC cut filter 48p, subsequent amplification with the low pass filter 49 p allows DC biascomponents to be overlapped with the vibration angular velocity signaland the DC components must be cut off once again in the cameramicrocomputer 411.

The memory circuit 412 p stores a vibration angular velocity signalwhich is sampled after 0.2 second, for example, elapses from turning onthe camera main switch, and the differential circuit 413 p calculates adifference between a stored value and the vibration angular velocitysignal so that the DC components are cut off. The DC components can becut off only roughly by these operations (since not only the DCcomponents but also actual hand vibrations are contained in thevibration angular velocity signal stored after 0.2 second elapses fromturning on the camera main switch) and the DC components are cut offsufficiently at a later step with the DC cut filter 414 p which isconfigured by a digital filter. A time constant of this DC cut filter414 p can also be changed in like manner of the analog DC cut filter 48p and gradually prolonged for 0.2 second as measured after 0.2 secondelapses from the camera main switch is turned on. Speaking concretely,the DC cut filter 414 p has a characteristic as to cut off DC signalcomponents having frequencies not higher than 10 Hz after 0.2 secondelapses from turning on the main switch, and then lower the cut offfrequency to 5 Hz, 1 Hz, 0.5 Hz and 0.2 Hz at intervals of 50 msec.

However, it may not be desirable to change the time constant whileconsuming time since a photographer may half depresses the camera mainswitch (turns on sw1) while the time constant is being changed, wherebythe camera may take a photograph upon completing photometry and adistance measurement. In such a case, the camera intercepts the changingof the time constant dependently on photographing conditions. When thephotometry indicates a photographing shutter speed of {fraction (1/60)}at a photographing focal length of 150 mm at which blur prevention maynot be so accurate, for example, the camera terminates the changing ofthe time constant upon obtaining a characteristic to cut off the DCcomponents having frequencies not higher than 0.5 Hz with the DC cutfilter 414 p (controls the changing of the time constant dependently ona product of the shutter speed multiplied by a photographing focallength). Therefore, the camera is capable of shortening the timerequired for changing the time constant, thereby making a shutter chancepreferential. At a faster shutter speed or a shorter focal length, thecamera terminates the changing of the time constant needless to say whenthe time constant is changed to obtain a characteristic to cut off theDC components having frequencies not higher than 1 Hz with the DC cutfilter 414 p or at a slower shutter speed or a longer focal length, thecamera inhibits photographing until the time constant is changed to thefinal level.

The integral circuit 415 p starts integrating output signals from the DCcut filter 414 p when the release button 43 a is half depressed (sw1 isturned on), thereby converting an angular velocity signal into an anglesignal. When changing of the time constant of the DC cut filter is notcompleted as described above, however, the integral circuit 415 p doesnot integrate the output signals until the changing of the time constantcompletes. Though not shown in FIG. 30, the integrated angle signal isadequately amplified dependently on data of a focal length and an objectdistance at that time, and converted so as to drive correction means 51in an adequate amount corresponding to a vibration angle. (Thiscorrection is required since the photographing optical system is variedand an eccentricity of the optical axis is changed dependently on adriven amount of the correction means 51.)

Upon completely depressing the release button 43 a (turning on sw2), thedriving of the correction means 51 is started in correspondence to avibration angle signal but care must be taken to prevent the correctionmeans 51 from abruptly starting a vibration preventive operation. Thememory circuit 416 p and the differential circuit 417 p are provided toprevent the correction means 51 from abruptly starting the vibrationpreventive operation. When the release button 43 a is depressedcompletely (sw2 is turned on), the memory circuit 416 p stores thevibration angle signal from the integral circuit 415 p. The differentialcircuit 417 p calculates a difference between the signal from theintegral circuit 415 p and a signal from the memory circuit 416 p.Accordingly, the differential circuit 417 p receives two signals whichare equal to each other and provides a driving target value signal of 0to the correction means 51 at a step where the switch SW2 is turned on,thereafter outputting signals successively increasing from 0. (Thememory circuit 416 p has a role to take an integral signal as an originat a step where the switch sw2 is turned on.) Accordingly, thecorrection means 51 is not driven abruptly.

The target value signal from the differential circuit 417 p is inputtedinto the PWM duty changing circuit 418 p. Though the correction lens 52is driven in correspondence to the vibration angle by applying a voltageor a current corresponding to the vibration angle to the coil 510 p ofthe correction means 51 (see FIG. 29), PWM drive is desirable to saveelectric power to be consumed by the correction means 51 and a drivingtransistor of the coil.

The PWM duty changing circuit 418 p changes a coil driving dutydependently on a target value. When a PWM has a frequency of 20 kHz, forexample, the PWM duty changing circuit sets duties “0” and “100” fortarget values “2048” and “4096” respectively provided from thedifferential circuit 417 p, and determines duties at equal intervalsbetween “0” and “100” in correspondence to target values. Thedetermination of the duties are finely controlled dependently not onlyon the target values but also photographing conditions of the camera(temperature, camera posture and condition of power supply) so that thevibration is corrected with a high accuracy.

An output from the PWM duty changing circuit 418 p is inputted into thedriving device 419 p which is a known driving device such as a PWMdriver and an output from the driving device 419 p is applied to thecoil 510 p (see FIG. 29) of the correction means 51 to correct thevibration. The driving device 419 p is turned on in synchronization withthe switch sw2 and turned off upon completion of film exposure. So longas the release button 43 a is half depressed (sw1 is turned on), theintegral circuit 415 p continues integration even after the completionof the exposure and the memory circuit 416 p stores a new integraloutput when the switch sw2 is turned on next time.

When the photographer stops half depressing the release button 43 a, theintegral circuit 415 p stops integrating the output from the DC cutfilter 414 p and resets itself. Resetting means to erase data which hasbeen so far accumulated by integration.

When the main switch is turned off, the vibration detection device 45 pis turned off to terminate a vibration prevention sequence.

When the output signal from the integral circuit 415 p exceeds apredetermined value, it is judged that the camera has been panned andthe time constant of the DC cut filter 414 p is changed. For example, acharacteristic to cut off DC components having frequencies not higherthan 0.2 Hz is changed to a characteristic to cut off DC componentshaving frequencies not higher than 1 Hz and an original time constant isresumed in a predetermined time. An amount of this change of the timeconstant is controlled dependently on a level of the output from theintegral circuit 415 p. Speaking concretely, the DC cut filter 414 p hasa characteristic so as to cut off DC components having frequencies nothigher than 0.5 Hz when the output signal exceeds a first thresholdvalue, a characteristic so as to cut off DC components havingfrequencies not higher than 1 Hz when the output signal exceeds a secondthreshold value or a characteristic so as to cut off DC componentshaving frequencies not higher than 5 Hz when output signal exceeds athird threshold value.

When the output of the integral circuit 415 p is remarkably high, theintegral circuit is once reset to prevent a calculation from beingsaturated (overflowing).

Though the DC cut filter 414 p is configured by starting operating after0.2 second elapses from the main switch is turned on in FIG. 30, thisconfiguration is not limitative and the DC cut filter 414 p may beconfigured by starting operating when the release button 43 a is halfdepressed. In such a case, the integral circuit 415 p is operated uponcompletion of the change of the time constant of the DC cut filter.

Though the integral circuit 415 p is also configured by startingoperating when the release button 43 a is half depressed (when sw1 isturned on), it may be configured by starting operating when the releasebutton 43 a is completely depressed (when sw2 is turned on). In such acase, the memory circuit 416 p and the differential circuit 417 p areunnecessary.

Though the DC cut filter 48 p and the low pass filter 49 p are disposedin the calculation device 47 p in FIG. 30, it is needless to say thatthese filters may be disposed in the vibration detection device 45 p.

FIGS. 31 through 33 are diagrams illustrating the correction means 51 indetail: FIG. 31 is a front view of the correction means 51, FIG. 32A isa side view as seen from a direction indicated by an arrow 32A in FIG.31, FIG. 32B is a sectional view taken along a 32B—32B line in FIG. 31and FIG. 33 is a perspective view of the correction means 51.

In FIG. 31, a correction lens 52 is fixed to a support frame 53 (thecorrection lens 52 comprises two lenses 52 a and 52 b which are fixed toa support frame 53, and a lens 52 c which is fixed to a base plate 54 asshown in FIG. 32B, thereby composing a lens group of a photographingoptical system).

A yoke 55 which is made of a ferromagnetic material is attached to thesupport frame 53, and permanent magnets 56 p and 56 y which are made ofneodymium or the like are adsorbed and fixed (indicated by hidden lines)to a rear surface of the yoke 55 in FIG. 31. Furthermore, three pins 53a which extend radially from the support frame 53 are fitted intoelongated holes 54 a formed in a side wall 54 b of the base plate 54.

The pins 53 a are fitted in the elongated holes 54 a with no play in adirection along an optical axis 57 of the correction lens 52 but theelongated holes 54 a extend in a direction perpendicular to the opticalaxis 57 as shown in FIGS. 32A and 33, whereby the support frame 53 isfreely movable along a plane perpendicular to the optical axis (asindicated by arrows 58 p, 58 y and 58 r) though it is restricted by thebase plate 54 in the direction along the optical axis 57. However, thesupport frame 53 is elastically restricted in each of the directions (58p, 58 y and 58 r) by a tension spring 59 which is stretched between ahook 53 b on the support frame 53 and a hook 54 c on the base plate asshown in FIG. 31.

Coils 510 p and 510 y are disposed on the base plate 54 so as to opposeto the permanent magnets 56 p and 56 y (indicated by partially hiddenlines). The yoke 55, the permanent magnet 56 p and the coil 510 p arearranged as shown in FIG. 32B (the permanent magnet 56 y and the coil510 y are similarly arranged) so that the support frame 53 is driven inthe direction indicated by the arrow 58 p when a current is supplied tothe coil 510 p or in the direction indicated by the arrow 58 y when acurrent is supplied to the coil 510 y.

A driven amount of the support frame 53 is determined by balance betweena spring constant of the tension springs 59 and a thrust which isgenerated by correlation between the coil 510 p, 510 y and the permanentmagnet 56 p, 56 y in each directions. That is, an amount of eccentricityof the correction lens 52 can be controlled on the basis of levels ofcurrents supplied to the coils 510 p and 510 y.

A photographing control described below is conceivable as a handvibration preventive measure other than the vibration prevention systemdescribed above.

A camera determines an exposure time (shutter speed) from luminance ofan object, brightness (an F value) of a photographic lens and a filmsensitivity, but when the exposure time exceeds a predetermined time,the exposure time is fixed at the predetermined time (the film is notexposed for a time longer than the predetermined time) to prevent animage from being degraded due to the hand vibration and a strobe islighted to compensate for under-exposure caused by the photographingcontrol. Speaking concretely, the exposure time is fixed at {fraction(1/60)} second and the strobe is lighted at luminance of an object whichrequires an exposure time longer than {fraction (1/60)} second (forexample {fraction (1/15)} second). This photographing control is capableof preventing at a certain degree an image from being degraded due tothe hand vibration of a photographer.

However, the photographing control described above does not make itpossible of take a favorable image of a photographic scene where strobelight does not reach a main object. When the exposure time is fixed atthe predetermined time for a photographic scene where a main object isapart about 7 meters from the camera, for example, the strobe lightcannot reach the main object, thereby making the main objectunder-exposed. Even when the strobe light reaches the main object, thestrobe light may not reach a background, thereby making itunder-exposed.

Though the hand vibration preventive measure can be improved byequipping a camera which performs the photographing control describedabove with the vibration prevention system, such a camera cannot copewith the photographing condition where the strobe light does not reachthe main object and expose the background adequately.

However, if the strobe light is not used, by using a camera whichperforms the photographing control described above and is equipped withthe vibration prevention system device described above, it is possibleto take a photograph with a long exposure time (since it lessens a fearof the hand vibration regardless of the long exposure time), therebyallowing both the main object and the background to be exposedadequately.

Accordingly, it is conceivable that the camera which is equipped withthe vibration prevention system is held by hand for photographing a darkobject, but the vibration prevention system has a limited capability,thereby posing a problem that camera may be held for too long a time forphotographing due to too much reliance on the vibration preventionsystem, thereby causing photographing to be failed by the handvibration.

SUMMARY OF THE INVENTION

In one aspect of the present invention, it provides a camera to which animage blur correction device is applied, comprising:

exposure time calculation means which calculates an exposure time incorrespondence to at least any of photometry data, sensitivity data ofan image recording medium and brightness of a photographic lens;

strobe photographing designation means which forces the camera toexecute strobe photographing when the exposure time calculated by theexposure time calculation means is longer than a first exposure time;

closing time setting means which forcibly fixes an exposure time at apredetermined exposure closing time (Tb or Td) regardless of acalculated result of the exposure time calculating means when theexposure time calculated by the exposure time calculation means islonger than the second exposure time; and

changing means which changes a combination of the first exposure timeand the second exposure time dependently on whether or not the imageblur correction device is used for photographing,

thereby configurating the camera by being capable of setting the firstexposure time and the second exposure time so as to be matched withphotographing with or without the image blur correction device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an electrical configuration of mainmembers of a camera preferred as a first embodiment of the presentinvention;

FIG. 2 is a flowchart showing operations of the main members of thecamera preferred as the first embodiment of the present invention;

FIG. 3 is a diagram summarizing control examples of photographingconditions of the camera preferred as the first embodiment of thepresent invention;

FIG. 4 is a flowchart partially showing operations of main members of acamera preferred as a second embodiment of the present invention;

FIG. 5 is a flowchart showing operations of the main members subsequentto those shown in FIG. 4;

FIG. 6 is a diagram summarizing control examples of photographingconditions of the camera preferred as the second embodiment of thepresent invention;

FIG. 7 is a flowchart showing operations of main members of a camerapreferred as a third embodiment of the present invention;

FIG. 8 is a diagram summarizing control examples of photographingconditions of the camera preferred as the third embodiment of thepresent invention;

FIG. 9 is a block diagram showing an electrical configuration of mainmembers of a camera preferred as each of fourth through sixthembodiments of the present invention;

FIG. 10 is a flowchart showing operations of the main members of each ofthe fourth through sixth embodiments of the present invention;

FIG. 11 is a flowchart showing operations to change a shutter closingtime for the camera preferred as the fourth embodiment of the presentinvention;

FIG. 12 is a diagram summarizing control examples of photographingconditions of the camera preferred as the fourth embodiment of thepresent invention;

FIG. 13 is a flowchart showing operations to change a shutter closingtime for the camera preferred as the fifth embodiment of the presentinvention;

FIG. 14 is a diagram summarizing control examples of photographingconditions of the camera preferred as the fifth embodiment of thepresent invention;

FIG. 15 is a flowchart showing operations to change a shutter closingtime for the camera preferred as the sixth embodiment of the presentinvention;

FIG. 16 is a block diagram showing an electrical configuration of mainmembers of a vari-focal camera preferred as a seventh embodiment of thepresent invention;

FIG. 17 is a flowchart showing operations of the main member of thevari-focal camera preferred as the seventh embodiment of the presentinvention;

FIG. 18 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when a sport mode is judged;

FIG. 19 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when a portrait mode is judged;

FIG. 20 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when a macro mode is judged;

FIG. 21 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when a night view mode (smallvibration) is judged.

FIG. 22 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when the night view mode (largevibration) is judged;

FIG. 23 is a flowchart showing operations which are executedsubsequently to those shown in FIG. 17 when an automatic mode is judged.

FIG. 24 is a flowchart showing operations which are executedsubsequently to those shown in FIGS. 18 through 23;

FIG. 25 is a diagram summarizing control examples of photographingconditions of the vari-focal camera preferred as the seventh embodimentof the present invention;

FIG. 26 is a flowchart showing operations of main members of avari-focal camera preferred as an eighth embodiment of the presentinvention;

FIG. 27 is a flowchart showing operations of the main members f avari-focal camera preferred as a ninth embodiment of the presentinvention.

FIG. 28 is an external view of a conventional compact camera equippedwith a vibration prevention system;

FIG. 29 is a perspective view showing an internal mechanism of thecamera shown in FIG. 28;

FIG. 30 is a block diagram showing an internal configuration of acalculation device shown in FIG. 29;

FIG. 31 is a front view of correction means of the camera shown in FIG.28;

FIGS. 32A and 32B are side views as seen from a direction indicated byan arrow 32A in FIG. 31 and a sectional view taken along a 32B—32B linein FIG. 31; and

FIG. 33 is a perspective view of the correction means shown in FIG. 31.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the present invention will be described in detail with reference tothe preferred embodiments illustrated in the accompanying drawings.

FIG. 1 is a block diagram showing an electrical configuration of mainmembers of a camera preferred as a first embodiment of the presentinvention, with other members omitted for simplicity of description. Thecamera is equipped with a blur prevention device such as that shown inFIG. 29.

In FIG. 1, input into a camera microcomputer 11 from a blur preventionswitch 12 (hereinafter referred to as IS switch) is a signal whichdenotes whether the vibration prevention device is to be set in anoperative condition or an inoperative condition during photographing.Furthermore, data of distance from the camera to a main object isinputted into the camera microcomputer 11 from a distance measuringdevice 15. On the basis of object luminance data, a film sensitivity andbrightness (an F value) of a photographic lens which are provided from aphotometry device (not shown), the camera microcomputer 11 calculates anexposure time, controls a shutter device 13 as described later on thebasis of the exposure time and simultaneously determines whether or nota strobe device 14 is to be used as occasion demands.

FIG. 2 is a flowchart showing operations of the main members of thecamera having the configuration described above. The operations arestarted upon completing preparations for photographing.

At a first step #1001, it is judged whether or not the IS switch 12inputs the command signal which commands use of the blur preventiondevice during photographing and when the use of the blur preventiondevice is commanded, the flow advances to a step #1007 or otherwise theflow advances to a step #1002. At the step #1002, the exposure timecalculated from the object luminance data, the film sensitivity and thebrightness (F value) of the photographic lens is compared with a strobelighting start time Ta and when the exposure time is longer than Ta({fraction (1/60)} second, for example), the flow advances to a step#1003 or otherwise to a step #1006. In this case where the exposure timecalculated from the film sensitivity and the brightness of thephotographic lens is shorter than Ta, the camera executes photographingwith this exposure time.

At the step #1003, the strobe device 14 is set in a condition where itis ready for lighting at exposuring. At a next step #1004, the exposuretime is compared with a shutter closing time Tb ({fraction (1/60)}second, for example) and when the exposure time is longer than Tb, theflow advances to a step #1005 or otherwise to a step #1006. In this casewhere the exposure time is shorter than Tb, the camera takes aphotograph with the obtained exposure time. At the step #1005, theexposure time is fixed at Tb to inhibit photographing with a exposuretime longer than Tb. At the successive step #1006, the object is exposedto the film corresponding to a shutter release operation by aphotographer.

In the case where the blur prevention device is not used, the flowdirectly advances to the step #1006 and immediately exposes the objectwith the exposure time determined above when the object is bright (theexposure time is shorter than {fraction (1/60)} second) due to be freefrom the fear of the hand vibration, but fixes the exposure time at Tband lights the strobe device for correcting exposure when the object isdark (the exposure time is longer than {fraction (1/60)} second) due tobe feared to be blurred by the hand vibration.

In the case where use of the blur prevention device is commanded at thestep #1001, the flow advances to the step #1007 as described above atwhich the exposure time is compared with a strobe lighting start time Tc({fraction (1/60)} second, for example) and when the exposure time islonger than Tc, the flow advances to a step #1008 or otherwiseimmediately advances to the step #1006 described above.

At the step #1008, the strobe device 14 is set in the condition where itis ready for lighting, the exposure time is compared with a shutterclosing time Td at a subsequent step #1009 and when the exposure time islonger than Td (¼ second, for example), the flow advances to a step#1010 or otherwise to the step #1006 described above. At the step #1010,the exposure time is fixed at Td (¼ second, for example) to inhibitphotographing with a longer exposure time.

That is, in the case where the blur prevention device is used, the flowdirectly advances to the step #1006 and the object is exposed when theobject is bright (the exposure time is shorter than {fraction (1/60)}second) due to be free from the fear of the hand vibration and the blurprevention device operates when the object is dark (the exposure time is{fraction (1/60)} second or longer) to lessen the fear of the handvibration, whereby it is enable to prolong the shutter closing time (to¼ second from {fraction (1/60)} second in the case where the blurprevention device is not used) and to allow not only the main object butalso the background to be exposed adequately.

The shutter closing time is set (at ¼ second, for example) even when theblur prevention device is used because too long an exposure time (1second, for example) produces a fear of the hand vibration even when theblur prevention device is used.

When the exposure time is Tc or longer, the strobe device 14 is lightedto keep still the object by lighting the strobe (as a measure to preventthe object vibration), and when the blur prevention device is used, thestrobe device 14 is lighted at object brightness which provides Tc({fraction (1/60)} second, for example) and an actual exposure time isdetermined in correspondence to the object brightness (shutter closingtime Td).

The photographing with an exposure time longer than the predeterminedstrobe lighting start time (Tc) is referred to as “slow synchrophotographing” which is capable of adequately exposing not only the mainobject but also the background to which strobe light cannot reach. (Whenthe blur prevention device is not used, a photograph may be blurred bythe hand and the camera must be fixed to a tripod.)

The first embodiment described above makes it possible to easily obtainfavorable photographs by controlling the photographing conditions forthe camera like those for a camera which is not equipped with thevibration prevention system when the blur prevention device is not usedand by executing the slow synchro photographing when the blur preventiondevice is used.

Ta and Tc (strobe lighting start times) as well as Td and Tb (shutterclosing times) described with reference to the flowchart shown in FIG. 2are not limitative by the condition described above, and Ta for startingthe strobe lighting may not be equal to Tc. FIG. 3 exemplifiescombinations of Ta, Tc, Td and Tb.

A condition (1) shown in FIG. 3 corresponds to the example ofphotographing control described above with reference to the flowchart inFIG. 2. Furthermore, the strobe lighting start times Tc and Ta may bechanged between photographing with the blur prevention device andphotographing without the blur prevention device as shown in a condition(2) in FIG. 3.

In the first embodiment described above, the strobe is lighted with thestrobe device 14 upon photographing when the exposure time calculatedfrom the object brightness, etc. is longer than Ta or Tc (for example,{fraction (1/60)} second or {fraction (1/30)} second). However, it isjudged whether or not the exposure time is longer than Td (¼ second, forexample) when the blur prevention device is used in this case, and thestrobe photographing is executed with the exposure time fixed at Td whenthe exposure time is longer than Td or otherwise the strobephotographing is executed with the strobe photographing with Ta or Tc({fraction (1/60)} second or {fraction (1/30)} second, for example).

Furthermore, in the first embodiment, it is judged whether or not theexposure time is longer than Tb ({fraction (1/60)} second, for example)when the blur prevention device is not used, and if longer, the strobephotographing is executed with the exposure time fixed at Tb orotherwise the strobe photographing is executed with Tb ({fraction(1/60)} second, for example).

Though the first embodiment provides only an effect which is similar tothat available with the conventional camera when the blur preventiondevice is not used, it controls photographing conditions for the slowsynchro photographing when the blur prevention device is used, therebymaking it possible to obtain a favorable photograph on which not onlythe main object but also the background is exposed adequately.

The strobe lighting start times Tc and Ta are changed in response to theconditions of photography with the vibration prevention system andphotography without the blur prevention device as in the condition (2)shown in FIG. 3, thereby making it possible to obtain the photograph bybetter use of characteristics of the vibration prevention system.

Second Embodiment

FIGS. 4 and 5 are flowcharts showing operations of main members of acamera preferred as a second embodiment of the present invention havinga circuit composition which is similar to that of the first embodimentand not described in particular.

In the second embodiment of the present invention, photographingcondition is changed between a case where strobe light can reach anobject and another case where the strobe light cannot reach the object.

Speaking concretely, the second embodiment includes an arrangement forpreventing hand vibration and object vibration using a strobe devicewhen an object is located within an area where strobe light reaches it,and for preventing under-exposure by prolonging a shutter closing time(an exposure time) when an object is located at a distance beyond reachof the strobe light.

The second embodiment includes an arrangement for positively using thestrobe device for the object located within the reach of the strobelight even when the blur prevention device is used. Since the blurprevention device suppresses the hand vibration at even when an exposuretime is prolonged to a certain degree, it is considered that the strobedevice may not be used so often but the movement of the object (objectvibration on a screen) is actually produced when the exposure time isprolonged. Accordingly, it is desirable to select an exposure time asshort as possible within a range where the object is exposed adequatelyand the strobe device is lighted to shorten an exposure time even whenthe blur prevention device is used.

Though the strobe device is used positively even when the blurprevention device is used, the shutter closing time is set later (byprolonging the exposure time) than that when the blur prevention deviceis not used so that a background which is outside the reach of thestrobe light is exposed adequately.

When the object is located at the distance beyond the reach of thestrobe light, it is needless to say that the blur prevention device isused, thereby exposing the object adequately and providing a photographhaving an image quality not degraded due to the hand vibration. Thoughthe exposure time is prolonged in this a case, the object is located ata long distance from the camera and the image quality is not degradeddue to the object movement (the object vibration on the screen). This isbecause the object vibration is less remarkable as the object is locatedat a longer distance from the camera.

Now, operations of the main members of the second embodiment of thepresent invention will be described with reference to the flowchartsshown in FIGS. 4 and 5. Steps at which operations of the secondembodiment are the same as those in FIG. 1 are denoted by the same stepnumbers and not described in particular.

At each of steps #2001 and #2002, it is judged whether or not an objectis in the strobe light reachable area. When distance data (data denotinga distance from the camera to the object) is inputted from the distancemeasuring device 15 shown in FIG. 1 into the camera microcomputer 11,the camera microcomputer 11 calculates the strobe light reachable area(distance) from brightness (F value) of a photographic optical system ata photographing time, a film sensitivity and a strobe guide number,compares the distance with the distance data from the distance measuringdevice 15 and judges whether or not the strobe light reaches the object.

Actually, the camera microcomputer judges more complicatedly. When anegative film is used, the camera microcomputer 11 judges that thestrobe light reaches an object which is located at a distance beyond thereach of the strobe light but is not to be exposed inadequately so much(for example, to be under-exposed at two steps) but when a positive filmis used, the camera microcomputer judges that the strobe light does notreach an object located which is located at a distance too long foradequate exposure. (Since the negative film has a large exposureallowance).

When it is judged that the strobe light does not reach the object at thestep #2001 or #2002, the flow advances to a step #1002 or #1007 andexecute an operation which is the same as that described with referenceto FIG. 2.

When it is judged that the strobe light reaches the object, on the otherhand, the flow advances to a step #2003 or #2007 shown in FIG. 5.Operations at steps #2003 through #2006 or steps #2007 through #2010 arethe same as those at the steps #1002 through #1005 shown in FIG. 4,except for times Te, Tf, Tg and Th which are to be judged.

On the basis of the determination of the use or not use the vibrationprevention system and the judgement that the strobe light reaches ordoes not reach the object as in the flowcharts shown in FIGS. 4 and 5,the strobe lighting start times Ta, Tc, Te and Tg, and the shutterclosing times Tb, Td, Tf and Th are set as shown in FIG. 6.

In FIGS. 4 and 5 also, photographing is executed only with the exposuretime calculated as described above with reference to the example shownin FIG. 1 when the camera microcomputer 11 skips steps (steps 1005,1010, 2006, 2010) to fix the exposure time.

FIG. 6 shows an example to control two kinds of photographingconditions. In the photographing conditions shown in FIG. 6, a strobemode is selectable in an auto mode (a mode in which the cameraautomatically judges whether or not a strobe is to be used dependentlyon luminance of an object), but a shutter closing time is controlled asshown in FIG. 6 even in a strobe off mode or a forcible strobe lightingmode.

When the strobe light reaches the object in an example mentioned ascondition (1) in FIG. 6, photographing conditions are the same betweenphotographing with the blur prevention system and photographing withoutthe blur prevention device. This is because an exposure time as short aspossible is preferable when an object is located at a short distancewithin the strobe light reachable area and the object movement (objectvibration on the screen) during exposuring is remarkable as describedabove. Accordingly, a short exposure time is selected and the strobe islighted to compensate for under-exposure though the blur preventiondevice prevents an influence due to the hand vibration even at a longerexposure time.

When an object is located at a distance beyond the strobe lightreachable area, the strobe lighting is actually ineffective, but thestrobe is lighted at a low object luminance (when the exposure time islonger than {fraction (1/30)} second) to compensate for under-exposureeven slightly and notify photographing to the object. When the object islocated at the distance beyond the strobe light reachable area, theshutter closing time is changed (the strobe lighting start time is keptunchanged) between the photographing with the blur prevention device andthe photographing without the blur prevention device. When the blurprevention device is used, the shutter closing time being prolong to ¼second for the photographing. This is because it is unnecessary toselect a short exposure time and the blur prevention device suppressesthe hand vibration when the object is located at the distance beyond thestrobe light reachable area and the object vibration is not remarkable.

Upon photographing without the blur prevention device, the reason whythe strobe lighting start time is changed between a condition where thestrobe light reaches the object and another condition where the strobelight does not reach the object, takes into consideration differentinfluences due to the object vibration described above. Furthermore, theshutter closing time is changed to compensate for under-exposure as faras possible while slightly sacrificing the object vibration.

In an example mentioned as a condition (2) in FIG. 6, the shutterclosing time is prolonged for the photographing with the blur preventiondevice even when the strobe light reaches the object.

In the example mentioned as the condition (1) described above, thestrobe light is used to compensate for the under-exposure when thestrobe light reaches the object. However, a background which is outsidethe strobe light reachable area is considerably under-exposed (becausethe shutter closing time is short). When the blur prevention device isused in the example mentioned as the condition (2), a long shutterclosing time is selected to expose the background adequately even in acondition where the object is near and strobe device is usable. Thoughthe exposure time is long in this case, the object is sufficientlyexposed by the strobe light and the object is scarcely exposed on thesubsequent exposure (while a shutter is kept open after completing thestrobe lighting), thereby making the object vibration on the screenunnoticeable (the object vibration on the screen is suppressed by thestrobe lighting).

When the strobe light does not reach the object, photographingconditions are controlled as in the example mentioned as the condition(1) described above.

In the second embodiment, when the exposure time calculated from theluminance of the object, etc. is longer than the shutter closing time Tdor Th, exposure is executed with the exposure time fixed at the shutterclosing time Td or Th, and if the blur prevention device is used in thiscase, the shutter closing time Td in case that the object is located farfrom the strobe light reachable area, is set longer than the shutterclosing time Th in case that the object is located at the short distancefrom the camera and within strobe light reachable area.

Accordingly, the hand vibration or the object vibration on the screen isprevented by using the strobe device when the object is located withinthe strobe light reachable area and it is possible to preventunder-exposure by selecting the long shutter closing time when theobject is located outside the strobe light reachable area.

When the calculated exposure time is longer than the strobe lightingstart time Tc or Tg, the strobe device is lighted. In this case, whenthe blur prevention device is used, the strobe lighting start time Tg incase that the object is located at the short distance from the camera orwithin the strobe light reachable area, is set shorter than the strobelighting start time Tc in case that the object is located at the longdistance from the camera and the strobe light does not reach the objector the object is far from the strobe light reachable area.

Accordingly, the noticeably object vibration on the screen which isproduced by the location of the object within the strobe light reachablearea, is prevented by, shortening the shutter closing time Th theunder-exposure resulting from the shortening of the shutter closing timeTh is compensated by using the strobe device positively.

Third Embodiment

FIG. 7 is a flowchart showing operations of main members of the thirdembodiment of the camera according to the present invention having acircuit composition which is similar to that of the first embodimentdescribed above and not described in particular.

The flowchart shows steps of operations to be executed before the step#1001 of the flowchart shown in FIG. 4 illustrating the secondembodiment described above.

In the third embodiment of the present invention, a photographing modewhich is selected by a photographing mode dial (not shown) is judged andphotographing condition is changed dependently on the selectedphotographing mode so that a strobe lighting start time and a shutterclosing time are not only changed dependently on whether or not thevibration prevention system is used and whether or not the strobe lightreaches the object (the object is within the strobe light reachablearea) but also delicately controlled the dependently on thephotographing mode, thereby allowing any person to easily take afavorable photograph.

After completing preparatory operations for photographing of the camera,the operations which are shown in the flowchart presented as FIG. 7 isstarted. At a step #3001 first, it is judged whether or not the automode is currently selected, the flow advances to a step #3005 when theauto mode is selected, strobe lighting start times Ta, Tc, Te and Tg aswell as shutter closing times Tb, Td, Tf and Th (described later indetail with reference to FIG. 8) are set respectively at the steep#3005, and the operations at the steps #1001 and later shown in FIG. 4are executed.

When the auto mode is not selected, the flow advances from the step#3001 to a step #3002 where it is judged whether or not a sport mode isselected and when the sport mode is selected, the flow advances to astep #3006 where the strobe lighting start times Ta, Tc, Te and Tg aswell as the shutter closing times Tb, Td, Tf and Th as shown in FIG. 7are set respectively, thereafter the operations at the steps #1001 andlater shown in FIG. 4 are executed.

When the sport mode is not selected, the flow advances from the step#3002 to a step #3003 where it is judged whether or not a macro mode isselected as a photographing mode, and when the macro mode is selected,the flow advances to a step #3007 where the strobe lighting start timesTa, Tc, Te and Tg as well as the shutter closing times Tb, Td, Tf and Thare set respectively (described later in detail with reference to FIG.8), thereafter the operations at the steps #1001 and later shown in FIG.4 are executed.

When the macro mode is not selected, the flow advances from the step#3003 to a step #3004 where it is judged whether or not a night viewmode is selected as a photographing mode and when the night view mode isselected, the flow advances to a step #3008 where the strobe lightingstart times Ta, Tc, Te and Tg as well as the shutter closing times Tb,Td, Tf and Th (described later in detail with reference to FIG. 8) areset respectively, thereafter the operations at the steps #1001 and latershown in FIG. 4 are executed.

When the night view mode is not selected, the flow advances from thestep #3004 to a step #3009 where it is judged that a portrait mode isselected as a rest photographing mode, and the strobe lighting starttimes Ta, Tc, Te and Tg as well as the shutter closing times Tb, Td, Tfand Th (described later in detail with reference to FIG. 8) are setrespectively, thereafter the operations at the steps #1001 and latershown in FIG. 4 are executed.

Operations of the third embodiment will be described with reference toFIG. 8 which summarizes the photographing modes mentioned above andphotographing condition control modes corresponding to the photographingmodes.

In the auto mode shown in FIG. 8, the auto mode is provided as a modefor little failure in general photographing (for example, snapshot)wherein when it is necessary to make an exposure time longer than anexposure time which may produce a fear of the hand vibration ({fraction(1/60)} seconds in the third embodiment) like that obtained by aconventional photographing control method, the exposure time isinhibited to prolong so as to compensate for under-exposure by using thestrobe device. Accordingly, a shutter closing time is equal to a strobelighting start time.

When the blur prevention device is turned on, the long shutter closingtime ({fraction (1/15)} second) is selected in this figure since thisexposure time is less capable of making the hand vibration in conditionthat the blur prevention device is turned. Actually, it is substantiallyless possible to produce the hand vibration even for a longer exposuretime (⅛ second), but the exposure time is calculated so as to have amargin (a short shutter closing time is selected) since the camera maybe handled in various ways. Accordingly, a background may beunder-exposed when the strobe light reaches an object or an object mayalso be slightly under-exposed when the strobe light does not reach theobject (needless to say, exposure is more adequate than that obtainedwithout using the blur prevention system), but importance is placed noton the exposure but on stability against the hand vibration.

Only the strobe lighting start time is not changed between thephotographing with the blur prevention device and the photographingwithout the blur prevention device since a photographer may be confusedby operations of the camera which are largely different apparentlybetween the photographing with the blur prevention device and thephotographing without the blur prevention device.

The sport mode is to be used for photographing an object which is movingat a high speed and it is to be noted here that the object movement (theobject vibration on the screen) cannot be prevented even when the blurprevention device eliminates the fear of the hand vibration on a longexposure time. For this reason, it is preferable not to unreasonablyprolong the exposure time in this mode even when the blur preventiondevice is used (not to set the shutter closing time at a late timing).

When the strobe light reaches the object, the photography is executedwith an exposure time which is as short as possible to cope with theobject vibration on the photographing screen and under-exposured stateis compensated by lighting the strobe. When the strobe light reaches anobject, in the third embodiment, both the shutter closing time and thestrobe lighting start time are set at {fraction (1/100)} second whetheror not the blur prevention device is used. When the strobe light doesnot reach the object, basically, photographing conditions aresubstantially set the same as those in the auto mode (an exposure timemay not be so short in this case since the object is located at adistance too long for the strobe light to reach the object and theobject vibration is not noticeable) but a shutter closing time is setshorter than that in the auto mode. This is because the object vibrationis not negligible when the shutter closing time is set to be as long asthat in the auto mode.

In the macro mode also, a strobe lighting start time and a short shutterclosing time are set short ({fraction (1/100)} second) when the strobelight reaches the object. This is because an image is degraded not onlydue to rotational vibrations (indicated by arrows 42 p and 42 y in FIG.28) which can be suppressed with the blur prevention device but alsoshift vibrations in parallel with a plane which is perpendicular to theoptical axis when the camera is brought close to the object for macrophotographing. The shift vibrations cannot be corrected since thesevibrations cannot be detected with a vibration detection device whichdetects a rotational angular velocity. Accordingly, to cope with theshift vibrations, a short exposure time is selected.

Considering a fact that a magnification is enhanced and the influencedue to the object vibration on the photographing screen is noticeable(for example, a flower swung by a wind) when the camera is brought closeto the object for the macro photographing, the short exposure time isset and under-exposure is compensated by the strobe lighting when thestrobe light reaches the object. When the strobe light does not reach anobject, photographing conditions is controlled as in the auto mode.

In the night view mode (or the slow synchro mode), a strobe lightingstart time is set similar to that in the auto mode but a shutter closingtime is set at ¼ second when the blur prevention device is turned on or{fraction (1/15)} seconds when the blur prevention device is turned off.The long shutter closing time is selected to expose a background asadequately as possible, thereby clearly photographing a neon sign and aChristmas tree, for example, existing in the background.

When the blur prevention device is turned on, the shutter closing timeis set at ¼ seconds. Though the hand vibration may be feared when thecamera is handled roughly for photographing with this exposure time, thephotographing is rather free from the fear of the hand vibration sinceit is based on a premise that a photographer intentionally selects thenight view mode and firmly holds the camera in this mode. When the blurprevention device is turned off, a shutter closing time is set {fraction(1/15)} second which is different from the shutter closing time in theauto mode and the hand vibration is feared. An operation manual for thecamera according to the present invention contains a clear descriptionto instruct the photographer to firmly hold the camera or use the tripodin this case like an operation manual for the conventional camera.

Furthermore, the third embodiment may be configured by forcibly turningon the blur prevention device when the night view mode is selected (thecamera has no night view mode in which the blur prevention device is notused).

In the portrait mode, the strobe is lighted whether or not the strobelight reaches an onject and whether or not the blur prevention device isturned on. (A strobe lighting start time of {fraction (1/250)} secondlisted in FIG. 8 is substantially the same as the strobe which is alwayslighted for photographing.) The strobe lighting gives a catch light toan eye of a person as an object, thereby making it possible to take aphotograph of the person having a vivid look (since a catch light can begiven even when the strobe light cannot sufficiently reach the object).

When the blur prevention device is turned on, the shutter closing timeis set at ⅛ second to expose the background adequately regardless of thestrobe light reaches the object. In the portrait mode, the shutterclosing time is longer than that in the auto mode so as to obtain apreferable portrait by photographing the background as bright aspossible (by exposing the background adequately).

In the portrait mode, the shutter closing time is shorter than that inthe night view mode to reduce the hand vibration since an image qualitydemanded for a photograph obtained in the portrait mode is higher thanthat for a photograph obtained in the night view mode. When the blurprevention device is turned off, the shutter closing time is controlledas in the auto mode.

Unlike the first embodiment or the second embodiment described above,the third embodiment described above is configured by delicatelycontrolling the strobe lighting start time and the shutter closing timedependently not only on whether or not the blur prevention device isturned on and whether or not the strobe light reaches the object butalso on the condition of the photographing mode, thereby allowing a userto easily take a favorable photograph in each of the photographing modeseven when he has no specialized knowledge in camera operation orcharacteristics of set photographing modes.

As understood from the foregoing description, the first through thirdembodiments of the present invention are capable of providing cameraswhich can adequately expose not only main objects but also other objectsexisting in backgrounds by making most of the characteristic of the blurprevention device.

Furthermore, the first through third embodiments of the presentinvention described above are capable of providing cameras which canprevent the objects from being under-exposed even when the objects arelocated at distance exceeding the reach of the strobe light.

Furthermore, the first through third embodiments of the presentinvention are capable of providing cameras which can prevent withoutfail the objects from being vibrated on screens and under-exposed whenthe object are located within the reach of the strobe light.

Moreover, the first through third embodiments of the present inventiondescribed above are capable of providing cameras which allow evenbeginners to take photographs without fail when any of the photographingmodes is selected.

Fourth Embodiment

FIG. 9 is a block diagram illustrating an electrical configuration ofmain members of a camera preferred as the fourth embodiment of thepresent invention, with other members omitted for simplicity ofdescription. The camera is equipped with the blur prevention deviceshown in FIG. 29 or the like.

In FIG. 9, a signal which determines whether or not the blur preventiondevice is turned on for photographing is inputted from a blur preventionswitch 112 (hereinafter referred to as an IS switch) to a cameramicrocomputer 111. Furthermore, luminance data of a main object isinputted from a photometry circuit 115. On the other hand, the cameramicrocomputer 111 controls an exposure time for a shutter (not shown) ina shutter device 113 and whether or not a strobe (not shown) is used onthe basis of photometric data from the photometry circuit 115, a filmsensitivity and brightness (F value) of a lens.

Furthermore, the camera microcomputer controls photographing conditionson the basis of a photographing mode selected condition input from amode selection member 114. The photographing mode is, for example, asport mode or a night view mode. In the sport mode which is selected forphotographing an object moving at a high speed, a fast shutter speed({fraction (1/100)} second, for example) is selected to preventvibrations caused by a movement of the object (object vibration on ascreen) and under-exposure is compensated by lighting a strobe. In thenight view mode, a slow shutter speed is allowed (the night view modeallows a shutter speed of 2 seconds at longest though a shutter speed isnot slower than {fraction (1/60)} second in an ordinary mode taking avibration during photographing into consideration) to expose both a mainobject and a background adequately in a dark photographing condition,and a strobe device is used dependently on luminance of the main object(for the slow synchro photographing).

Furthermore, input into the camera microcomputer 111 are temperaturedata of an operating environment at a photographing time, camera posturedata (informing whether the camera is set in a horizontal or verticalposture) and data informing whether or not the camera is fixed to atripod from a temperature detection circuit 117, a posture detectioncircuit 118 and a tripod detection circuit 119 composed of a switchdisposed in a tripod hole respectively.

Furthermore, vibration data is inputted into the camera microcomputer111 from a vibration detection device 116 (corresponding to thevibration detection devices 45 p and 45 y shown in FIG. 29) so that thevibration data is used not only for vibration prevention control butalso for photographing condition control in the fourth embodiment.

FIG. 10 is a flowchart descriptive of operations of the main members ofthe camera having the configuration described above or concrete exposuretime control operations for photographing which start upon completingpreparations for photographing.

At a step #11001 first, the camera microcomputer 111 judges whether ornot an exposure time calculated on the basis of the photometry data fromthe photometry circuit 115 is longer than Ta ({fraction (1/100)} second,for example), terminates this flow when the exposure time is not longerthan Ta and executes an exposure operation by controlling the shutterdevice 113 on the bassis of the calculated exposure time.

When the calculated exposure time is longer than Ta, the cameramicrocomputer proceeds from the step #11001 to a step #11002 where itjudges whether or not the exposure time is longer than Tb ({fraction(1/60)} second, for example). When the exposure time is not longer thanTb, the camera microcomputer proceeds directly to a step #11004, butwhen the exposure time is longer than Tb, the camera microcomputer 111proceeds to a step #11003 where it fixes the exposure time at Tb so thata longer exposure time is not used for photographing and proceeds to thestep #11004. At the step #11004, the camera microcomputer sets thestrobe device ready for lighting so that it lights at an exposure time.

That is, when an object is bright (the exposure time is {fraction(1/100)} second or shorter), the hand vibration is not feared andexposure is executed with the exposure time or when the object is dark(the exposure time is {fraction (1/60)} second or longer), since thehand vibration is f eared, the exposure time is fixed at Tb (fixed Tb isreferred to as “a shutter closing time”) and the strobe is lighted at aphotographing time for correcting under-exposure.

Even in FIG. 10, photographing executed with the calculated exposuretime as in the example shown in FIG. 1 when the camera microcomputerdoes not pass through a step (step #11003) at which the exposure time isfixed.

Values of the Ta and Tb are actually changed dependently onphotographing modes and operating conditions of the blur preventiondevice. FIG. 11 is a flowchart exemplifying steps of operations tochange values of the Ta and Tb and description will be made below withreference to this flowchart. These operations are executed aftercompleting preparatory operations for photographing and before startingthe flow of operations shown in FIG. 10.

After completing the preparatory operations for photographing in FIG.11, the camera microcomputer 111 judges at a step #11005 whether or notuse of the blur prevention device is denoted by the IS switch 112 andwhen use of the blur prevention device is not denoted, proceeds to astep #11006 where the camera microcomputer judges whether or not thenight view mode is selected by the mode selection member 114. When thenight view mode is selected, the camera microcomputer proceeds to a step#11007 where it sets the shutter closing time at Tb to terminate thisflow of operations and proceeds to the flow of operations shown in FIG.10.

In the night view mode where the blur prevention device is not used, thecamera microcomputer sets the shutter closing time at 2 seconds like theconventional camera. Since the photographer of course knows in this casethat the blur prevention function is inoperative and the night view modeis selected, the photographer pays sufficient attention to the handvibration during the slow shutter photographing and takes a measure toprevent the vibration, for example, by fixing the camera to a tripod.

When the night view mode is not selected at the step #11006, the cameramicrocomputer 11 proceeds to a step #11008 where it sets the shutterclosing time Tb at {fraction (1/60)} second to terminate this flow ofoperations and proceeds to the flow of operations shown in FIG. 10.

Since the photographer does not pay attention to the hand vibration andthe blur prevention device is not used for photographing in this casewhere the night view mode is not selected, the camera microcomputer setsthe shutter closing time Tb at {fraction (1/60)} second or the like andinhibits a longer exposure time from being selected as a measure toprevent the hand vibration during exposure.

When the camera microcomputer judges that use of the blur preventiondevice is denoted at the step #11005, the camera microcomputer proceedsto a step #11009 where it judges whether or not the night view mode isselected as at the step #11006 and when the night view mode is notselected, the camera microcomputer proceeds to a step #11010 where itsets the shutter closing time Tb at {fraction (1/15)} second toterminate this flow of operations as at the step #11008 since the nightview mode is not selected, thereafter proceeding to the flow ofoperations shown in FIG. 10. In this case the shutter closing time Tb isset at {fraction (1/15)} second which is different from the shutterclosing time at the step #11008 since the hand vibration is not fearedwhen the blur prevention device is used for photographing.

When the night view mode is selected at the step #11009, the cameramicrocomputer 111 proceeds to a step #11011 where it judges whether ornot the camera is mounted on a tripod (whether or not a tripod is used)on the basis of a signal from the tripod detection circuit 119 and whenthe tripos is used, the camera microcomputer proceeds to a step #11013where it sets the shutter closing time Tb at 2 seconds to terminate thisflow of operations, thereafter proceeding to the flow of operationsshown in FIG. 10.

Since the use of the tripod eliminates the fear of image degradation dueto the vibration, the shutter closing time Tb is set at 2 seconds at thestep #11013 so that the object is exposed as adequately as possible withthe long shutter closing time.

When the camera microcomputer judges that the tripod is not used at thestep #11011, it proceeds to a step #11012 where it judges whether or nota vibration is smaller than a predetermined value on the basis of aninput from the vibration detection device 116 and proceeds to a step#11015 when the vibration is smaller than the predetermined value. Insuch a case where a vibration is small as described above, the vibrationis extremely small even when the camera is not fixed to a tripod butplaced on the ground or pressed to a tree for photographing and thecamera microcomputer proceeds to the step #11015.

The camera microcomputer 111 sets the shutter closing time at 2 secondsat the step #11015 as at the step #11013 to terminate this flow ofoperations and proceeds to the flow of operations shown in FIG. 10. Theshutter closing time is set at 2 seconds because the camera eliminatesthe fear of image degradation due to the vibration when it is fixed forphotographing as it is mounted on the tripod.

When the camera microcomputer 111 judges that the vibration is largerthan the predetermined value at the step #11012, it proceeds to a step#11014 where it judges whether the camera is set in the horizontal or avertical posture on the basis of a signal from posture detection circuit118 and when the camera has the vertical posture, the cameramicrocomputer 111 proceeds to a step #11017 where it sets the shutterclosing time Tb at ⅛ second to terminate this flow of operations,thereafter proceeding to the flow of operations shown in FIG. 10.

Since the camera is designed for easier handling at its horizontalposture, it is liable to be vibrated at its vertical posture. Therefore,the shutter closing time Tb is set shorter for the vertical posture ofthe camera than that for the vertical posture at the step #11017.

When the camera microcomputer 111 judges that the camera is set in thehorizontal posture at the step #11014, it proceeds to a step #11016where it judges whether or not a temperature is low (0 degree or lower)in an operating environment for photographing on the basis of a signalfrom the temperature detection circuit 117 and when the temperature islow, the camera microcomputer proceeds to a step #11019 where it setsthe shutter closing time Tb at ⅛ second to terminate this flow ofoperations, thereafter proceeding to the flow of operations shown inFIG. 10.

When the temperature is low in the operating environment forphotographing, the shutter closing time Tb is set at short as at thestep # 11017 because the numb hands enhance a possibility to cause thehand vibration when the temperature is low in the operating environment.

When it is judged that the temperature is not low in the operatingenvironment for photographing at the step #11016, it proceeds to a step#11018 where it sets the shutter closing time Tb at ¼ second toterminate this flow of operations, thereafter proceeding to the flow ofoperations shown in FIG. 10.

When the night view mode is selected for photographing with the blurprevention device, the flow often proceeds in an order of the steps#11017, #11018 and #11018 (since t he camera is held by hand forphotographing). The shutter closing time Tb for the night view modewithout the blur prevention device (2 seconds) is longer than theshutter closing time for the night view mode with the blur preventiondevice (¼ second or ⅛ second).

Though it may ordinarily be considered that the use of the blurprevention device which lessens the fear of the hand vibration allows alonger shutter closing time to be set, the photographing conditions arecontrolled as described above to prevent photographing failures frombeing made due to too much reliance on the blur prevention device whichmay lead to photographing of quite dark objects while holding the cameraby hands.

Needless to say, the photographing is adequately executed by lightingthe strobe, and a large vibration generated by the exposure time at 2seconds can be prevented though the background allows slightunder-exposure due to the shutter closing time of ¼ second or ⅛ secondwhich is longer than 2 seconds. The shutter closing time can beprolonged by placing the camera on a tripod or the ground.

The shutter closing times Tb described with reference to FIG. 11 aresummarized in FIG. 12.

In the fourth embodiment described above, prevents the hand vibration isprevented without fail by fixing the exposure time at the predeterminedshutter closing time (the step #11003 in FIG. 10) when the exposure timecalculated from the photometry data (luminance of the object, etc.) islonger than the predetermined shutter closing time ({fraction (1/60)}second, for example) and urging the strobe lighting at a photographingtime. Furthermore, in the fourth embodiment, the shutter closing time Tbfor the photographing with the blur prevention device is set shorterthan that for the photographing without the blur prevention device (thesteps #11017, #11018 and #11019 in FIG. 11) (when the night view mode(slow synchro photographing) is selected as a photographing mode inparticular), thereby preventing photographing from being failed bytaking a photograph a quite dark object while holding the camera byhands through too much reliance on the vibration preventive effect ofthe blur prevention device.

In the fourth embodiment, the more adequate photography is executed evenin the night view mode using the blur prevention device by setting theshutter closing time Tb as long as that for the photography without theblur prevention device (the steps #11013 and #11015 in FIG. 11) when thecamera is placed on the ground or the tripod to lower a vibration duringthe photography. In such a case, even when the above blur preventiondevice is used, a similar effect can be obtained by making inoperativemeans which sets a shutter closing time shorter than that forphotography without the blur prevention device.

In order to prevent photographing from being failed due to too muchreliance on the vibration preventive effect of the blur preventiondevice, the shutter closing time is set short (the steps #11017 and#11019 in FIG. 11) since the hand vibration is easily generated when thecamera has the vertical posture or an ambient temperature is low at aphotographing time.

The fourth embodiment which controls these photographing conditionsallows any person to easily obtain photographs free from vibrations.

Fifth Embodiment

In contrast to the fourth embodiment in which is judged whether or notthe camera is firmly fixed by utilizing the outputs from the tripoddetection circuit 119 or the vibration detection device 116 and theshutter closing time Tb is determined based on the result of thisjudgement, the fifth embodiment of the present invention adopts aconfiguration which does not use the above-mentioned tripod detectioncircuit 119 but provides a similar effect to configure a camera morecompact. Other components of the fifth embodiment are the same as thoseof the fourth embodiment described above.

In the fifth embodiment of the present invention, “hand held night viewmode” and “tripod night view mode” are selectable as the night view modewith the mode selection member 114. The tripod night view mode only usesa long shutter closing time, whereas the hand held night view modesadopts a shutter closing time which is not so long to cope with the handvibration.

FIG. 13 is a flowchart showing operations main members (corresponding tothe operations shown in the flowchart presented as FIG. 11) of a camerapreferred as the fifth embodiment which start upon completingpreparatory operations for photography.

At a step #12001 first, the camera microcomputer 111 judges whether ornot the night view mode is selected as a photographing mode by the modeselection member 114 and proceeds to a step #12002 when the night viewmode is selected or otherwise proceeds to a step #12003.

At the step #12002, the camera microcomputer 111 judges whether thenight view mode is the hand held night view mode or the tripod nightview mode and when the hand held night view mode is selected, the cameramicrocomputer 111 proceeds to a step 12008 where it judges whether ornot the blur prevention device is used. As a result, when the blurprevention device is used, the camera microcomputer 111 proceeds to astep #12010 where it sets the shutter closing time at ¼ second toterminate this flow of operations, thereafter proceeding to the flow ofoperations shown in FIG. 10.

Since it is necessary to take a measure to prevent the hand vibrationfor photographing a night view while holding the camera by hand, ashutter closing time is set not so long but set at ¼ second even whenthe blur prevention device is used.

When the camera microcomputer 11 judges that the blur prevention deviceis not used at the step #12008, it proceeds to a step #12009 where itset the shutter closing time Tb at {fraction (1/15)} second.

Since attention must be paid to the hand vibration when the blurprevention device is not used, the shutter closing time is set at{fraction (1/15)} second as described above.

When the camera microcomputer 11 judges that the tripod night view modeis selected at the step #12002, it proceeds to a step #12005 where itprolongs the shutter closing time Tb to 2 seconds since the handvibration is not feared. When the tripod night view mode is selected,the blur prevention device is unnecessary and may be turned offforcibly.

When the camera microcomputer 11 judges that a mode other than the nightview mode is selected at the step #12001, it proceeds to the step #12003as described above where it judges whether or not the blur preventiondevice is used as at the step #12008 and proceeds to a step #12007 whenthe blur prevention device is used or otherwise proceeds to a step#12006.

Though it is unnecessary to select a long shutter closing time for themode other than the night view mode, a shutter closing time is setlonger within a range which allows no hand vibration so that a mainobject and its background are exposed adequately.

At the step 12007, the camera microcomputer 111 sets the shutter closingtime at {fraction (1/15)} second. This is because the hand vibration isnot feared up to this shutter closing time when the blur preventiondevice is not used. At the step #12006, on the other hand, the cameramicrocomputer 111 sets the shutter closing time at {fraction (1/60)}second as a measure to prevent the hand vibration while the blurprevention device is not used.

FIG. 14 summarizes relationship among the photographing modes, use ofthe blur prevention device and the shutter closing times.

In the fifth embodiment described above, the camera includes the handheld night view mode and the tripod night view mode as the night viewmode, the shutter closing time of the hand held night view mode is setlonger that for the ordinary photographing mode and the shutter closingtime of the tripod night view mode is set further longer since the handvibration is less feared. The fifth embodiment which is configured asdescribed above makes it possible to omit the tripod detection circuit,thereby permitting simplifying a configuration of the camera,configuring the camera more compact and lowering a manufacturing cost ofthe camera, and allows a photographer to take a measure to prevent thehand vibration by himself while freely selecting a shutter closing time.

Sixth Embodiment

In the fourth and fifth embodiments described above, the shutter closingtime Tb is changed dependently on factors such as turning on or off ofthe vibration prevention device, the photographing modes and camerapostures. However, the camera is liable to be vibrated in conditionswhich are produced by factors other than those mentioned above. When thecamera is operated for photography immediately after it is held by aphotographer, for example, it is often not held firmly and liable to bevibrated.

In the sixth embodiment of the present invention, a shutter closing timeis set short when the camera is operated for photography a short timeafter it is held as a measure to cope with a vibration and theunder-exposure caused due to the short shutter closing time iscompensated by lighting the strobe. For example, a timer is started whenthe release button is half depressed (s1 is turned on) and the shutterclosing time Tb is inhibited from being prolonged before a predeterminedtime elapses.

FIG. 15 is a flowchart showing operations of members which changes ashutter closing time in a camera as the sixth embodiment which startwhen the release button is depressed completely (s2 is turned on). Thetimer starts when the release button is half depressed (s1 is turnedon).

At a step #13001, the camera microcomputer 111 judges whether or not acount time t on the timer which starts upon the half depression of therelease button reaches 0.4 second and when the count t reaches 0.4second, the camera microcomputer 111 proceeds to a step #13002 where itjudged whether or not the count time t on the timer reaches 1 second.When the count time t exceeds 1 second, the camera microcomputer 111proceeds to a step #13003 where it sets the shutter closing time Tb at ¼second to terminate this flow of operations. When the count time t doesnot reach 1 second, the camera microcomputer 111 proceeds to a step#13005 where it sets the shutter closing time Tb at ⅛ second toterminate this flow of operations.

When the count time t does not reach 0.4 second at the step #13001, thecamera microcomputer 11 proceeds to a step #13004, where it sets theshutter closing time at {fraction (1/15)} second to terminate this flowof operations.

On the basis of the flow of operations described with reference to FIG.10, on the basis of a photographing shutter speed on exposure time orthe like calculated from the brightness the shutter closing time Tbdetermined as described above, it is determined whether or not thestrobe is to be used on the basis of the flow described with referenceto FIG. 10.

In the sixth embodiment described above, since the shutter closing timeTb is set at a short time (the step #13004 in FIG. 15) the photographingfailure due to the hand vibration can be reduced in such a case wherethe camera is operated for photographing (the release button isdepressed completely) immediately after the camera is held (the releasebutton is half depressed).

Though the timer is started when the release button is half depressed inthis case, it may be modified to judge that the camera is held, forexample, when an output from the vibration detection device becomeswithin a predetermined range, start the timer, and the shutter closingtime Tb is changed dependently on a time elapsed from the start of thetimer to the complete depression of the release button. (The timer isreset when the output from the vibration detection device exceeds thepredetermined value during the counting operation of the timer.)

Though the flow advances to the step #13004 where it sets the shutterclosing time Tb at {fraction (1/15)} second when the count time t on thetimer does not reach 0.4 second, every moment a time elapsed from thestart of the timer to the complete depression of the release button arechecked and the shutter closing time is prolonged as the elapsed time islonger.

As understood from the foregoing description, the fourth through sixthembodiments of the present invention described above provide cameraswhich are capable of securely preventing photographing from being faileddue to too much reliance on the vibration preventive effect of the blurprevention device.

Furthermore, the fourth through sixth embodiments of the presentinvention described above provide cameras which are capable ofphotographing objects while making most of the characteristic of theblur prevention device and exposing the objects more adequately.

Furthermore, the fourth through sixth embodiments of the presentinvention described above provide cameras which are configured by beingcompact, manufactured at low costs and capable of photographing nightviews with adequate exposure not only when the cameras are held by handsbut also when the camera are fixed to tripods.

Moreover, the fourth through sixth embodiments of the present inventiondescribed above provide cameras which are capable of photographing withsuppressed vibration even when photographing operations are started ashort time after start of preparatory operations for photographing.

Seventh Embodiment

FIG. 16 is a block diagram showing an electrical configuration of mainmembers of a vari-focal camera preferred as the seventh embodiment ofthe present invention wherein other components of the camera are omittedfor simplicity of description.

When a signal is inputted from a camera main switch 2114 into a cameramicrocomputer 211 in FIG. 16, the camera microcomputer 211 moves aphotographic lens barrel from a collapsed condition to a condition wherean optical system is ready for photographing and opens a lens barrier.Furthermore, the camera microcomputer 211 starts a vibration detectiondevice 219 at this time. A photographing mode selected by a photographeris inputted into the camera microcomputer 211 from a photographing modeinput member 2112. The vari-focal camera is equipped with a sport modesuited for photographing an object which is moving, a portrait modesuited for closeup photographing a person, a macro mode suited forcloseup photographing an object and a night view mode suited forphotographing a night view.

A strobe mode is inputted into the camera microcomputer 211 from astrobe mode input member 2111. The strobe mode includes a strobe offmode which does not use a strobe device, a strobe on mode which forciblylight the strobe device and a strobe auto mode which controls the strobedevice so that it is lighted or not dependently on luminance of anobject, directions of rays and the like, and is capable of determiningto active or inactive a red-eye moderating function during the strobelighting.

When the photographer manipulates blur a prevention switch 218 todetermine whether or not vibration is to be corrected duringphotographing, data of the determination is inputted into the cameramicrocomputer 211. When the photographer holds the camera andmanipulates a zoom operation member 215, a signal is inputted into thecamera microcomputer 211, which controls a zoom driving device 216 tochange a photographing focal length. When the photographer halfdepresses a release member (release button) 2113 after the photographingfocal length is determined as described above, the camera microcomputer211 obtains a distance to an object (distance measuring data) by drivinga distance measuring circuit 213 at this timing and controls on thebasis of this data an AF driving device 2115, which adjust a focallength of the photographic optical system by driving partially orentirely the photographic lens barrel on the basis of the distancemeasuring data. Since vibration data is inputted into the cameramicrocomputer 211 from the vibration detection device 219 at this time,the camera microcomputer 211 judges from the vibration data whether thecamera is held by hand or fixed to a tripod or the ground. Though thevibration detection device 219 may be started when the release member2113 is half depressed, in the seventh embodiment, the vibrationdetection device 219 is started when the camera main switch is turned onsince the vibration detection device 219 exhibits a low vibrationdetection reliability immediately after it is started.

When the photographer half depresses the release member 2113, the cameramicrocomputer 211 obtains luminance of the object (photometry data) bydriving a photometry circuit 212 at this timing, calculates an exposuretime on the basis of photographing data so far obtained such as thephotometry data, a sensitivity and a kind of a film, an operatingcondition of the vibration prevention system, the photographing focallength, brightness of a lens, a photographing mode, a selection of thevibration correction, the distance measuring data and a vibrationsignal, and determines whether or not the strobe device is to be used.

When the release member 2113 is completely depressed, the cameramicrocomputer 211 starts correcting a vibration by controllingcorrection means 2110 having the configuration shown in FIG. 29 on thebasis of a vibration signal provided from the vibration detection device219. Then, the camera microcomputer 211 exposes the film by controllinga shutter driving device 214 and lights the strobe device 217 asoccasion demands.

In the seventh embodiment, a film exposure time and the strobe lightingare delicately controlled dependently on photographing conditions forthe camera as described below with reference to FIGS. 17 through 24.

When the release member 2113 is half depressed, the camera microcomputerstarts operations shown in FIG. 17.

At a step #21001 first, drives the photometry circuit 217, the distancemeasuring circuit 213 and the vibration detection device 219 are driven,thereby obtaining the photometry data, the distance measuring data andthe vibration data. At this time, photographing mode data and strobemode data have already been input from the photographing mode inputmember 2112 and the strobe mode input member 2111 respectively. Let usassume that photographing focal length data has already been determined.

At a next step #21002, it is judged whether or not the sport mode isselected as a photographing mode and the flow advances to a step #21007when the sport mode is selected or otherwise advances to a step #21003.At the step #21003, it is judged whether or not the portrait mode isselected as the photographing mode and the flow advances to s step#21018 when the portrait mode is selected or otherwise advances to astep #21004. At the step #21004, it is judged whether or not the macromode is selected as the photographing mode and the flow advances to astep #21019 shown in FIG. 20 when the macro mode is selected orotherwise advances to a step #21005.

At the step #21005, it is judged whether or not the night view mode isselected as the photographing mode and the flow advances to a step#21006 when the night view mode is selected or otherwise advances to astep #21062 shown in FIG. 23. At the step #21006, it is judged whetheror not a vibration is smaller than a predetermined value and proceeds toa step #21040 shown in FIG. 21 when it judges that the camera is fixedto the tripod or the ground and the vibration is small or the flowadvances to a step #21051 shown in FIG. 22 when it is judged that thevibration is larger than the predetermined value and the camera is heldby hand.

Operations in each photographing mode will be described below withreference to FIGS. 18 through 23.

First, operations in the sport mode will be described with reference toa flowchart shown in FIG. 18.

At the step #21007 shown in FIG. 18, it is judged from a state of theblur prevention (IS) switch 218 whether or not the blur preventiondevice is in an operating condition and the flow advances to a step#21008 when vibration correction is denoted for exposure or otherwiseadvances to a step #21015.

At the step #21008, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the photometry circuit213 on the basis of a film sensitivity and a photographing focal lengthat this time and the flow advances to a step #21009 when the strobelight reaches the object or otherwise advances to a step #21010. Whenthe object is not exposed adequately by the strobe light butunder-exposed two or three steps, it is judged that the strobe lightreaches the object.

At the step #21009, it is judged whether or not the photographing focallength is on a tele side or a wide side taking as a boundary, forexample, a boundary of a focal length is 90 mm of with respect to a newphotographing system camera (hereinafter referred to as ASP camera),when a photographing focal lengths is within from 30 to 150 mm. The flowadvances to a step #21011 when the focal length is longer than 90 mm orotherwise it advances a step #21012.

At the step #21011, the strobe lighting start time and the shutterclosing time are set at “Tb={fraction (1/125)} second” and “Tc={fraction(1/125)} second” respectively, and the flow advances to a step #21073shown in FIG. 24. The strobe lighting start time Tb is used to controlthe camera so that the strobe is lighted when the shutter speed Tacalculated from the photometry data (object luminance data), the filmsensitivity data and the brightness of the lens at the photographingfocal length does not exceeds {fraction (1/125)} second. The shutterclosing time is used to control the camera so that it is inhibited fromexecuting photographing with a shutter speed longer than {fraction(1/125)} second but it executes photographing with an exposure time of{fraction (1/125)} second when the shutter speed Ta as described abovedoes not exceed {fraction (1/125)} second.

At the step #21012, similarly the strobe lighting start time Tb and theshutter closing time Tc are set at “Tb={fraction (1/60)} second” and“Tc={fraction (1/60)} second” respectively, and proceeds to the step#21073 shown in FIG. 24.

In a conventional camera which is not equipped with the blur preventiondevice, for executing the photographing in condition with thephotographing focal lengths from 30 to 150 mm, it is necessary toprevent the hand vibration by controlling a shutter speed as describedbelow.

Assuming that a camera of an ASP format has an aspect ratio which issubstantially the same as that of a film of a 135 format, a focal lengthof the camera is about 1.4 times as long as a focal length expressed interms of the 135 format. Therefore, the focal lengths of 30 to 150 mmare converted into focal lengths of 42 to 210 mm of a conventionalcamera. It is generally said that a shutter speed of 1/focal length isrequired to prevent the hand vibration of a camera of the 135 format andit is desirable to operate a camera which has such focal length s at ashutter speed of {fraction (1/45)} to {fraction (1/250)} second forphotographing. Furthermore, the blur prevention device exhibits aneffect to prevent the hand vibration corresponding to two steps in termsof a shutter speed and makes it possible to operate the camera at ashutter speed of {fraction (1/10)} to {fraction (1/60)} second.

When the blur prevention device is used, it is therefore sufficient toset the shutter closing time Tc at {fraction (1/60)} and {fraction(1/10)} second in a zoom tele condition and in a zoom wide conditionrespectively, but in the sport mode where an object moves speedily, theobject vibration may be produced though the hand vibration is notproduced at a slow (long) shutter speed. This object vibration can beprevented by enhancing the shutter speed and is more liable to beproduced at a higher photographing magnification. That is, the objectvibration is liable to be produced when an object is close to the camerain the zoom tele condition and when the object moves speedily of course,whereby a shutter speed of {fraction (1/60)} to {fraction (1/125)}second is required for the camera which has the focal lengths describedabove.

For this reason, the shutter closing time Tc is not prolonged at thestep #21011 or #21012 even when the blur prevention device is used.Furthermore, strobe lighting start time Tb is set short since the objectmay be under-exposed when the shutter closing time Tc is short and thestrobe is lighted early to stop a movement of the object.

When it is judged that the strobe light does not reach the object, theflow advances as described above from the step #21008 to the step #21010where it is judged whether or not the photographing focal length is onthe tele side or the wide side and when the photographing focal lengthis long, it advances to a step #21014 or otherwise advances to a step#21013.

At the step #21013, the strobe lighting start time Tb is set at MAXsince the strobe light does not reach the object. The expression MAXmeans the time which is set as a shutter time longer than a longest timeof the shutter speed Ta set in the camera and “Tb=MAX” means that thestrobe is not lighted. Furthermore, the shutter closing time Tc is setat {fraction (1/15)} second and the flow advances to the step #21073shown in FIG. 24. The strobe lighting is inhibited for electric powersaving and the shutter closing time is set at {fraction (1/15)} secondto prevent an object from being under-exposed since the camera is set inthe zoom wide condition and the object is located at a long distancebeyond the reach of the strobe light when the flow advances to the step#21013. In addition, the long shutter closing time Tc poses no problemssince a photographing magnification is low and the object vibration isnot feared when camera is in the zoom wide condition and the object islocated at the long distance.

At the step #21014, the strobe lighting start time is also set at MAX toinhibit the strobe from being lighted and the shutter closing time Tc isset at “Tc={fraction (1/60)} second”, thereafter the flow advances tothe step #21073 shown in FIG. 24. In this case, the shutter closing timeTc is set at {fraction (1/60)} second since the camera is set in thezoom tele condition and the strobe is not lighted, thereby making itnecessary to compensate for under-exposure. In this case also, theobject vibration is not feared since the camera is located at the longdistance from the object.

When the correction of vibration during exposure is not denoted at thestep #21007, the flow advances to a step #21015 where it is judgedwhether the photographing focal length is on the tele side or the wideside and when the photographing focal length is long, the flow advancesto a step #21016 or otherwise the advances to a step #21017.

At the step #21016, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/250)} second” and“Tc={fraction (1/250)} second” respectively, thereafter the flowadvances to the step #21073 shown in FIG. 24. Since the camera is set inthe zoom tele condition for photographing without the blur preventiondevice, the shutter closing time Tc is set at {fraction (1/250)} secondand the strobe is lighted to compensate for under-exposure.

At the step #21017, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/60)} second” and“Tc={fraction (1/60)} second” respectively, thereafter the flow advancesto the step #21073. Since the camera is set in the zoom wide conditionfor photographing without the blur prevention device, the shutterclosing time Tc is set at {fraction (1/60)} second to prevent the handvibration and the object vibration.

Now, description will be made of operations in the portrait mode withreference to a flowchart shown in FIG. 19.

At a step #21018 shown in FIG. 19, it is judged whether or not the blurprevention device is in an operating condition and when the blurprevention is denoted for exposure, the flow advances to a step #21019or otherwise advances to a step #21026.

At the step #21019, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the distance measuringcircuit 213, a film sensitivity and a photographing focal length at thattime and when the strobe light reaches the object, the flow advances toa step #21020 or otherwise advances to a step #21021. It is judged thatthe strobe light reaches the object when the object will not be exposedadequately to the strobe light but under-exposed at two or three steps.

At the step #21020, it is judged whether or not the photographing focallength is on the tele side or the wide side and when the photographingfocal length is long, the flow advances to a step #21022 or when thephotographing focal length is short, the flow advances to a step #21023.

At the step #21022, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb=MIN” and “Tc={fraction (1/60)} second”,thereafter the flow advances to the step #21073 shown in FIG. 24. Theexpression MIN means, a shutter time shorter than a longest time of theshutter speed Ta set by the camera and “Tb=MIN” means that the strobe isalways lighted.

At the step #21023, similarly the strobe lighting start time and thenshutter closing time Tc are set at “Tb=MIN” and “Tc={fraction (1/30)}second”, thereafter the flow advances to the step #21073 shown in FIG.24.

In the portrait mode, the strobe is always lighted to give a catch lightto the object. The shutter closing time Tc is prolonged to a limit levelfor the photographing with the blur prevention device to adequatelyexpose the background to which the strobe light does not reach. Takingthe object vibration into consideration in the portrait mode, theshutter closing time Tc is set not at a longest {fraction (1/10)} secondbut at {fraction (1/30)} second even in the zoom wide condition.

When it is judged that the strobe light does not reach the object, theflow advances as described above from the step #21019 to the step #21021where it is judged whether the photographing focal length is on the teleside or the wide side and when the photographing focal length is long,the flow advances to a step #21025 or when the photographing focallength is short, advances to a step #21014.

At the step #21024 also, the strobe lighting start time Tb and theshutter closing time Tc are set at MIN and {fraction (1/15)} secondrespectively, thereafter the flow advances to the step #21073 shown inFIG. 24. Though the strobe light does not reach the object, the strobeis lighted to obtain a vivid photograph of a person by reflecting thestrobe light even slightly on an eye of the person. Furthermore, theshutter closing time Tc is set at {fraction (1/15)} second since theobject is located at a long distance and the object vibration is notfeared.

At the step #21025 also, the strobe lighting start time Tb is set at MINso that the strobe is always lighted and the shutter closing time Tc isset at {fraction (1/30)} second, thereafter the flow advances to thestep #21073 shown in FIG. 24. To expose the person as adequately aspossible in the portrait mode, the shutter closing time Tc is set at{fraction (1/30)} second which is one step longer than the shutter timeof {fraction (1/60)} second which is a limit of the hand vibration inthe zoom tele condition.

When the vibration correction during exposure is not denoted, the flowadvances as described above from the step #21018 to the step #21026where it is judged whether the photographing focal length is on the teleside or the wide side and when the photographing focal length is long,the flow advances to a step #21027 or otherwise advances to a step#21028.

At the step #21027, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb=MIN” and “Tc={fraction (1/250)} second”respectively, thereafter the flow advances to the step #21073 shown inFIG. 24. Since the photography is executed in the zoom tele conditionwithout using the blur prevention device in this case, the shutterclosing time Tc is set at {fraction (1/250)} second as a measure toprevent the hand vibration and the strobe is always lighted to obtain acatch light.

At the step #21028, the strobe lighting start time and the shutterclosing time Tc are set at “Tb=MIN” and “Tc={fraction (1/45)} second”respectively, thereafter the flow advances to the step #21073 shown inFIG. 24. Since the photography is executed in the zoom wide conditionwithout using the blur prevention device in this case, the shutterclosing time Tc is set at {fraction (1/45)} second as a measured toprevent the hand vibration.

Now, description will be made of operations in the macro mode withreference to a flowchart shown in FIG. 20.

At a step #21029 shown in FIG. 20, it is judged whether or not the blurprevention device is in the operating condition and when the vibrationcorrection is denoted for exposure, the flow advances to a step #21030or otherwise advances to a step #21037.

At the step #21030, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the distance measuringcircuit 213 as well as a film sensitivity and a photographing focallength at that time and when the strobe light reaches the object, theflow advances to a step #21031 or otherwise advances to a step #21032.It is judged that the strobe light reaches the object when the objectwill be under-exposed at two or three steps though it will not beexposed adequately to the strobe light.

At the step #21031, it is judged whether the photographing focal lengthis on the tele side or the wide side and when the photographing focallength is long, the flow advances to s step #21033 or when thephotographing focal length is short, the flow advances to a step #21034.

At the step #21033, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/125)} second” and“Tc={fraction (1/125)} second” respectively, thereafter the flowadvances to the step #21073 shown in FIG. 24. At the step #21034, thestrobe lighting start time Tb and the shutter closing time Tc are alsoset at “Tb={fraction (1/125)} second” and “Tc={fraction (1/125)} second”respectively, thereafter the flow advances to the step #21073 shown inFIG. 24.

The shutter closing time Tc is set at {fraction (1/125)} second in boththe zoom tele condition and the zoom wide condition because the shiftvibration governs the camera vibration when the object is rather closeto the camera as in the macro mode.

As already described above, the blur prevention device corrects thevibration by detecting rotational vibrations around the vertical andhorizontal axes of the camera with the vibration sensor. However, thecamera is subjected not only the rotational vibrations but also theshift vibrations which are in directions in parallel with the planeperpendicular to the optical axis such as those produced by pushing therelease member 2113. Though it is sufficient to correct only therotational vibrations in an ordinary photographing condition where therotational vibrations govern the vibrations applied to the camera,influences due to the shift vibrations are more remarkable as the objectis closer to the camera. In the macro mode, image blur due to the shiftvibrations are not negligible in the macro mode. This blur cannot becorrected because this shift vibration cannot be detected by thevibration sensor using an angular velocity unit. Therefore acountermeasure of shortening the shutter speed is provided to preventthe shift vibration. Furthermore, vibrations of an object, for example,vibrations of a flower swung by wind are problematic since amagnification is rather high in the macro mode. The shutter closing timeTc is set short also as a measure to prevent such vibrations of anobject.

When it is judged that the strobe light does not reach the object at thestep #21030, the flow advances as described to the step #21032 where itis judged whether the photographing focal length is on the tele side orthe wide side and when the photographing focal length is long, the flowadvances to a step #21036 or otherwise advances to a step #21035.

At the step #21035, the strobe lighting start time Tb is set at MAX toinhibit the strobe from being lighted and the shutter closing time Tc isset at {fraction (1/15)} second, thereafter the flow advances to thestep #21073 shown in FIG. 24. The strobe is inhibited from being lightedsince the strobe light does not reach the object and the strobe lightingis useless. The shutter closing time Tc is set at {fraction (1/15)}second since the object is located at a long distance and the shiftvibrations are not feared.

At the step #21036 also, the strobe lighting start time is set at MAX toinhibit the strobe from being lighted and the shutter closing time isset at {fraction (1/60)} seconds, thereafter the flow advance to thestep #21073 shown in FIG. 24.

When the correction of vibration is not denoted for exposure, the flowadvances as described above from the step #21029 to the step #21037where it is judged whether the photographing focal length is on the telewide or the wide side and when the photographing focal length is long,the flow advances to a step #21038 or otherwise to a step #21039.

At the step #21038, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/250)} second” and“Tc={fraction (1/250)} second” respectively, thereafter the flowadvances to the step #21073 shown in FIG. 24. Since the blur preventiondevice is not used in the zoom tele condition, the shutter closing timeTc is set at {fraction (1/250)} second as a measure to prevent the handvibration and the strobe is lighted to compensate for under-exposure.

At the step #21039, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/125)} second” and“Tc={fraction (1/125)} second” respectively, thereafter the flowadvances to the step #21073 shown in FIG. 24. Since the blur preventiondevice is not used in the zoom wide condition and a magnification may behigh in the macro mode, the shutter closing time Tc is set at {fraction(1/125)} second as a measure to prevent the object vibration.

Referring to a flowchart shown in FIG. 21, description will be madebelow of operations in the night view mode in a case where the camera isset in a posture subjected to small vibrations (when it is judged thatthe camera is fixed to a tripod or the ground).

At a step #21040 shown in FIG. 21, it is judged whether or not the blurprevention device in the operating condition and when the correction ofvibration for exposure is denoted, the flow advances to a step #21041 orotherwise advances to a step #21048.

At the step #21041, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the distance measuringcircuit 213 as well as a film sensitivity and a photographing focallength at that time, and when the strobe light reaches the object, theflow advances to a step #21042 or otherwise advances to a step #21043.Unlike the photographing modes which have been described above, in thenight view mode, it is judged that the strobe light reaches the objectwhen the object will be under-exposed at three or four steps though itwill not be adequately exposed to the strobe light. This is becauseunder-exposure can be compensated for even slightly for an object so faras it is located at a distance which is nearly infinite (10 m, forexample).

At the step #21042, it is judged whether the photographing focal lengthis on the tele side or the wide side and when the photographing focallength is long, the flow advances a step #21044 or otherwise advances toa step #21045.

At the step #21044, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/45)} second” and “Tc=2seconds” respectively, thereafter the flow advances to the step #21073shown in FIG. 24. At the step #21045, similarly the strobe lightingstart time Tb and the shutter closing time Tc are set at “Tb={fraction(1/45)} second” and “Tc=2 seconds” respectively, thereafter the flowadvances to the step #21073 shown in FIG. 24.

The strobe lighting start time Tb is set at {fraction (1/45)} in boththe zoom tele condition and the zoom wide condition because no lightingof the strobe provides a photograph having a better atmosphere ratherthan lighting of the strobe even in the night view mode. Furthermore,since the camera is fixed to the tripod or the ground (to reducevibrations), the hand vibration is not feared and the object is exposedadequately even with the long shutter closing time Tc. Accordingly, aphotograph having brilliant colors by irradiating the object with thestrobe light is obtained when the strobe light reaches to the object andselect a long exposure time which is so-called slow synchrophotographing is executed for obtaining adequately exposure for abackground located outside the reach of the strobe light.

When it is judged that the strobe light does not reach the object at thestep #21041, the flow advances to the step #21043 where it is judgedwhether the photographing focal length is on the tele side or the wideside and when the photographing focal length is long, the flow advancesto a step #21047 or otherwise advances to a step #21046.

At the step #21046, the strobe lighting start time Tb is set at MAX toinhibit the strobe from being lighted and the shutter closing time Tc isset at 2 second, thereafter the flow advances to the step #21073 shownin FIG. 24. The strobe lighting is inhibited because a close-range viewwill be photographed, thereby making it impossible to favorablyphotograph a distant view if the strobe is lighted in this flow ofoperations set for photographing the distant view.

At the step #21047 also, the strobe lighting start time Tb is set at MAXto inhibit the strobe lighting and the shutter closing time Tc is set at2 seconds, thereafter the flow advances to the step #21073 shown in FIG.24.

At the steps #21046 and #21047, the shutter closing time Tc is set at 2seconds because the camera is scarcely subjected to vibrations, freefrom image blur due to the vibrations even with the long exposure timeand used to photograph a distant view with adequate exposure.

When the vibration correction for exposure is not denoted, the flowadvances as described above to the step #21048 where it is judgedwhether the photographing focal length is on the tele side or the wideside and when the photographing focal length is long, the flow advancesto a step #21049 or otherwise advances to a step #21050.

At the step #21049, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tc={fraction (1/250)} second” and “TC=2seconds” respectively, thereafter the flow advances to the step #21073shown in FIG. 24. Since the photography in the zoom tele condition isexecuted without using the blur prevention device in this case, thestrobe lighting start time Tc is set at {fraction (1/250)} second as ameasure to prevent the hand vibration and the shutter closing time Tc isset at 2 seconds to adequately expose the background.

At the step #21050, the strobe lighting start time and the shutterclosing time Tc are set at “Tb={fraction (1/45)} second” and “Tc=2seconds” respectively, thereafter the flow advances to the step #21073shown in FIG. 24. Though the photography in the zoom wide conditionwithout using the blur prevention device in this case, the strobelighting start time is set at {fraction (1/45)} second as a measure toprevent the hand vibration.

Referring to a flowchart shown in FIG. 22, description will be made ofoperations for photographing in the night view mode when the camera isset in a posture subjected to large hand vibration.

At a step #21051 shown in FIG. 22, it is judged whether or not the blurprevention device is in the operation condition and when the vibrationcorrection for exposure is denoted, the flow advances to a step #21052or otherwise advances to a step #21059.

At the step #21052, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the photometry circuit213 as well as a film sensitivity and a photographing focal length atthat time, and when the strobe light reaches the object, the flowadvances to a step #21053 or otherwise advances to a step #21054. As inthe night view mode where the hand vibration is small, it is judged thatthe strobe light reaches the object when the object will beunder-exposed three or four steps though it will not be exposedadequately to the strobe light.

At the step #21053, it is judged whether the photographing focal lengthis on the tele side or the wide side and when the photographing focallength is long, the flow advances to a step #21055 or otherwise advancesto step #21056.

At the step #21055, the strobe lighting start Tb and the shutter closingtime Tc are set at “Tb={fraction (1/45)} second” and “Tc=⅛ second”respectively, thereafter the flow advances to the step #21073 shown inFIG. 24. At the step #21056, the strobe lighting start time Tb is alsoset at “Tb={fraction (1/45)} second” and the shutter closing time Tc isset at “Tc=½ second”, thereafter the flow advances to the step #21073shown in FIG. 24.

Though it is necessary to set the shutter closing time at {fraction(1/60)} second in the tele condition or {fraction (1/10)} second in thewide condition to prevent the hand vibration when the camera is held byhand, the shutter closing time Tc is set at ⅛ second in the telecondition or ½ second in the wide condition to photograph the backgroundmore clearly by prolonging the shutter closing time Tc since the objectvibration can be prevented at certain degrees by the strobe lighting andthe background which is dark is negligibly affected by slight handvibration.

When it is judged that the strobe light does not reach the object at thestep #21052, the flow advances to a step #21054 where it is judgedwhether the photographing focal length is on the tele side or the wideside and when the photographing focal length is long, the flow advancesto a step #21058 or otherwise advances to a step #21057.

At the step #21057, the strobe lighting start time Tb is set at MAX toinhibit the strobe lighting and the shutter closing time Tc is set at ½second, thereafter the flow advances to the step #21073 shown in FIG.24. The strobe lighting is inhibited since a short-range view isphotographed when the strobe is lighted, thereby making it impossible tofavorably photograph a distant view which is a target in this flow ofoperations.

At the step #21058 also, the strobe lighting start time Tb is set at MAXto inhibit the strobe lighting and the shutter closing time Tc is set at⅛ second, thereafter the flow advances to the step #21073 shown in FIG.24.

When the vibration correction for exposure is not denoted, the flowadvances as described above from the step #21051 to the step #21059where it is judged whether the photographing focal length is on the teleside or the wide side and when the photographing focal length is long,the flow advances to a step #21060 or otherwise advances to a step#21061.

At the step #21060, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/250)} second” and “Tc=2seconds” respectively, thereafter the flow advances to the step #21073shown in FIG. 24. Since the photography in the zoom tele condition isexecuted without using the blur prevention device in this case, thestrobe lighting start time Tb is set at “{fraction (1/250)} second” as ameasure to prevent the hand vibration and the shutter closing time Tc isset at 2 seconds to expose the background adequately.

At the step #21061, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/45)} second” and “Tc=2seconds” respectively, thereafter the flow advances to the step #21073shown in FIG. 24. Though the photography in the zoom wide condition isexecuted without using the blur prevention device in this case, thestrobe lighting start time Tb is set at {fraction (1/45)} second as ameasure to prevent the hand vibration. The photographing conditions isthe same as those in the night view mode where the hand vibration issmall.

Now, description will be made of operations in the auto mode withreference to a flowchart shown in FIG. 23.

The auto mode is a standard mode for general snapshot and when the automode is selected, the flow advances as described above from the step#21005 shown in FIG. 17 to a step #21062 shown in FIG. 23. At the step#21062, it is judged whether or not the blur prevention device is in theoperating condition and when the vibration correction for exposure is tobe executed, the flow advances to a step #21063 or otherwise advances toa step #21070.

At the step #21063, it is judged whether or not the strobe light reachesthe object from the distance measuring data from the photometry circuit213 as well as a film sensitivity and a photographing focal length atthat time and when the strobe light reaches the object, the flowadvances to a step #21064 or otherwise advances to a step #21065.

At the step #21064, it is judged whether the photographing focal lengthis on the tele side or the wide side and when the photographing focallength is long, the flow advances to a step #21066 or otherwise advancesto a step #21067.

At the step #21066, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/60)} second” and“Tc={fraction (1/60)} second”, thereafter the flow advances to the step#21073 shown in FIG. 24. At the step #21067 also, the strobe lightingstart time and the shutter closing time Tc are set at “Tb={fraction(1/15)} second” and “Tc={fraction (1/15)} second”, thereafter the flowadvances to the step #21073 shown in FIG. 24.

Since the photography is executed with the blur prevention device inthis flow of operations, the shutter closing time Tc is set at {fraction(1/60)} second in the tele condition or {fraction (1/15)} second in thewide condition and the strobe lighting start time Tb which is equal tothe strobe lighting start time is set to compensate for under-exposure.

When it is judged that the strobe light does not reach the object at thestep #21063, the flow advances as describe above to the step #21065where it is judged whether the photographing focal length is on the teleside or the wide side and when the photographing focal length is long,the flow advances to a step #21069 or otherwise advances to a step#21068.

At the step #21068, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/15)} second” and“Tc={fraction (1/15)} second”, thereafter the flow advances to the step#21073 shown in FIG. 24. At the step #21069 also, the strobe lightingstart time and the shutter closing time Tc are set at “Tb={fraction(1/60)} second” and “Tc={fraction (1/60)} second”, thereafter the flowadvances to the step #21073 shown in FIG. 24.

When the vibration correction for exposure is not denoted, the flowadvances as described above from the step #21062 to the step #21070where it is judged whether the photographing focal length is on the teleside or the wide side and when the photographing focal length is long,the flow advances to a step #21071 or otherwise advances to a step#21072.

At the step #21071, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/250)} second” and“Tc={fraction (1/250)} second”, thereafter the flow advances to the step#21073 shown in FIG. 24. Since the photography in the zoom telecondition is executed without using the blur prevention device in thiscase, the strobe lighting start time Tb is set at {fraction (1/250)}second to prevent the hand vibration and the strobe is lighted tocompensate for under-exposure when object brightness corresponds to ashutter closing time longer than {fraction (1/250)} second.

At the step #21072, the strobe lighting start time Tb and the shutterclosing time Tc are set at “Tb={fraction (1/45)} second” and“Tc={fraction (1/45)} second” respectively, thereafter the flow advancesto the step #21073 shown in FIG. 24. Though the photography in the zoomwide condition is executed without using the blur prevention device, thestrobe lighting start time Tb is set at {fraction (1/45)} second toprevent the hand vibration so that the strobe is lighted to compensatefor under-exposure when object luminance corresponds to a strobelighting start time which is longer than {fraction (1/45)} second.

After the photographing conditions have been set as described above ineach photographing mode, the flow advances to the step #21073 shown inFIG. 24.

At the step #21073 in FIG. 24, the shutter speed Ta is calculated fromthe photometry data obtained with the photometry circuit 212 as well asbrightness of the photometric lens and a film sensitivity at that time.At a next step #21074, the shutter speed Ta is compared with the strobelighting start time Tb and when the shutter speed Ta is longer than thestrobe lighting start time Tb, the flow advances to a step #21075 orotherwise advances to a step #21080.

At the step #21075, the shutter speed Ta is compared with the shutterclosing time Tc and when the shutter speed Ta is longer than the shutterclosing time Tc, the flow advances to a step #21076 or otherwiseadvances to a step #21079.

At the step #21076, an exposure time is fixed to be actually used forphotographing at the shutter closing time Tc and the flow advances to astep #21077. At the step #21079, an exposure time is fixed to beactually used for photographing at the shutter speed Ta and the flowadvances to the step #21077. That is, the exposure time is set to beactually used for photographing at the shutter speed Ta or the shutterclosing time Tc whichever is the shorter.

At the step #21077, it is judged a strobe mode and this flow ofoperations is terminated when the strobe off mode is selected. That is,the use of the strobe is inhibited for photographing. When the strobemode is not the strobe off mode, the flow advances to a step #21078where the strobe is set so that it is lighted for photographing, therebyterminating this flow of operations.

Accordingly, the strobe is lighted for photographing when the strobemode is not the strobe off mode and the shutter speed Ta is longer thanthe strobe lighting start time Tb.

When the shutter speed Ta is shorter than the strobe lighting start timeTb at the step #21074, the flow advances as described above to the step#21080 where an exposure time is fixed to be used actually forphotographing at the shutter speed Ta and the flow advances to a step#21081. At the step #21081, it is judged whether not the strobe on modeis selected and when this mode is selected, the flow advances to a step#21082 or otherwise this flow of operations is terminated. At the step#21082, the strobe is set so that it is lighted for photographing,thereby terminating this flow of operations.

Accordingly, the strobe is not lighted when a mode other than the strobeon mode is selected and the shutter speed Ta is shorter than the strobelighting start time Tb.

FIG. 25 summarizes the strobe lighting start times Tb and the shutterclosing times Tc in the photographing conditions of the camera describedabove.

In the seventh embodiment described above, the photographing conditionsare changed dependently on whether or not the blur prevention device isin the operating condition and using a combination of a plurality ofphotographing focal lengths.

Speaking concretely, an object is exposed with an exposure time fixed atthe shutter closing time Tc when the object has luminance which providesan exposure time calculated on the basis of the object luminance or thelike, longer than the shutter closing time Tc; the shutter closing timeTc is prolonged when the blur prevention device is used or when thephotographing focal length is short; the strobe lighting is executedwhen the exposure time is longer than the strobe lighting start time Tb;and the strobe lighting start time Tb is prolonged when the blurprevention device is used or when the photographing focal length islong. Furthermore, the shutter closing time Tc is set longer than thestrobe lighting start time Tb when the blur prevention device is usedand the photographing focal length is short.

Furthermore, the photographing conditions is changed by usingcombinations of the reach of the strobe light and photographing focallengths.

Speaking concretely, the strobe lighting is executed when the exposuretime calculated from the object luminance, etc. is longer than thestrobe lighting start time Tb, the strobe lighting start time Tb is setlonger than that for a long photographing focal length when the objectis outside the reach of the strobe light and the photographing focallength is short, and the strobe lighting start time Tb is prolonged whenthe blur prevention device is used. Furthermore, an exposure time isfixed at the shutter closing time Tc when the blur prevention device isused and the exposure time is longer than the shutter closing time Tc,and the shutter closing time Tc is prolonged when a main object isoutside the reach of the strobe light.

Moreover, the photographing conditions may be changed by usingcombinations of the operating conditions of the blur prevention device,the photographing modes and the photographing focal lengths.

Accordingly, in the seventh embodiment, it is made possible to obtain afavorable photograph by delicately controlling the photographingconditions and prevent photographing from being failed due to too muchreliance on the blur preventive device.

Eighth Embodiment

In the seventh embodiment described above, the strobe lighting starttime Tb and the shutter closing time Tc are changed dependently on thephotographing focal length, a distance from the camera to the mainobject (whether or not the strobe light reaches the main object),operating condition of the blur prevention device and photographingmode.

Though the control of the shutter closing time Tc described above iseffective to prevent the hand vibration, a dark object (which makes theshutter closing time Tc operative) may not be exposed adequately.

Though an exposure inadequate at a certain degree can be corrected at aprint stage in case of a photographing which uses a negative film, aninadequate exposure produces a remarkable influence on a photographingresult in case of a photographing which uses a positive film.

In the eighth embodiment of the present invention, the shutter closingtime Tc is changed dependently on a kind of a film (whether the film ispositive or negative) so that the shutter closing time Tc is madeinoperative as far as possible when the camera uses a positive filmwhich makes even slightly inadequate exposure problematic.

FIG. 26 is a flowchart showing operations of main members of avari-focal camera preferred as the eighth embodiment of the presentinvention which are to be executed successively to the operations shownin FIGS. 18 through 23 described with reference to the seventhembodiment described above. That is, the operations shown in FIG. 26 areexecuted in place of those shown in FIG. 24. Operations at steps #21073and later shown in FIG. 26 are similar to those shown in FIG. 24 andwill not be described in particular.

At a step #22001, it is judged whether or not a charged film is positiveor negative and when the film is positive, the flow advances to a step#22002 or otherwise to the step #21073. At the step #22002, it is judgedwhether or not a photographing length is the zoom wide and when the zoomwide is selected, the flow advances to a step #22003 or otherwise thecamera microcomputer proceeds to the #21073. At the step #22003, theshutter closing time Tc determined in FIGS. 18 through 23 is set at alevel one step longer and the flow advances to the step #21073.

For example, the shutter closing time Tc is set at {fraction (1/30)}second when the shutter closing time is set at {fraction (1/60)} secondin the preceding flow or at 4 seconds when the shutter closing time Tcis set at 2 seconds in the preceding flow of operations.

By executing the operations described above, the shutter closing time Tcis set at the level one step longer in the zoom wide condition only forphotographing with the positive film. Accordingly, the occasions whereexposure is made inadequate is relatively reduced by the operation ofthe shutter closing time Tc, thereby making it possible to executephotographing favorably with the positive film.

Though the influence due to the hand vibration is more remarkable whenthe shutter closing time Tc is set at the level one step longer, it ispreferable to give a higher priority to the under-exposure preventivemeasure since most of photographers who use positive films are mostlyaccustomed to handling of cameras, have certain degree of knowledge inthe hand vibration by themselves and firmly hold the cameras to preventthe hand vibration.

In the zoom tele condition where the hand vibration poses a seriousproblem in image blur, however, the shutter closing time Tc is notchanged at the longer level even when the positive film is used.

In the eighth embodiment described above, an exposure time is fixed atthe shutter closing time Tc when the exposure time calculateddependently on object luminance, etc. is longer than the shutter closingtime Tc, and the shutter closing time Tc is prolonged when thephotographing focal length is short and the positive film is used,thereby making it possible to moderate the problem that inadequateexposure affects an image surface when the positive film is used.

Ninth Embodiment

In the eighth embodiment described above, the shutter closing time Tc ischanged dependently on the photographing focal length and the kind ofthe film. Paying attention to a fact that the image blur due tovibration can be suppressed at a certain degree at rather slow shutterspeeds when the photographers are skilled in photographing with the blurprevention device, the shutter closing time Tc may be changeddependently on the kind of film and a condition of the blur preventiondevice.

Since most of the photographers who use the positive films areaccustomed to handling of the cameras as described above, thephotographers themselves have the certain degree of knowledge in thehand vibration and can take photographs scarcely affected by vibrationeven rather slow shutter speeds using the blur prevention device.

When a positive film is charged in a camera which is equipped with theblur prevention device, it is therefore possible to reduce the imagedeterioration due to under-exposure by setting a longer shutter closingtime Tc.

FIG. 27 is a flowchart showing operations of main members of avari-focal camera preferred as the ninth embodiment of the presentinvention which are to be executed successively to those shown in FIGS.18 through 23 described with reference to the seventh embodiment. Thatis, the operations shown in FIG. 27 are executed in place of those shownin FIG. 24. Operations at steps #21073 in FIG. 27 are similar to thoseshown in FIG. 24 and will not be described in particular.

At a step #22001, it is judged whether or not a charged film is positiveor negative and when the film is positive, the flow advances to a step#23001 or otherwise advances to the step #21073. At the step #23001, itis judged whether or not the blur prevention device is used and when theblur prevention device is used, the flow advances to a step #23003 orotherwise advances to the step #21073.

Accordingly, the operation of the shutter closing time Tc makes exposureinadequate relatively less frequently and favorable photographing isexecuted even with the positive film.

Though the longer shutter closing time Tc allows the influence due tothe hand vibration to be more remarkable, an under-exposure preventivemeasure is made prior since most of photographers are accustomed tohandling of cameras and can reduce image blur due to the hand vibrationeven at rather slow shutter speeds using the blur prevention device.

The case wherein the shutter closing time Tc is reset when the positivefilm is used is not limited by the shutter closing time Tc in the zoomwide condition described in the ninth embodiment, like in the eighthembodiment described above. For example, the Tc may reset not only whenthe blur prevention device is used but also only when an object islocated at a distance beyond the reach of the strobe light (since aphotograph is not under-exposed when the strobe light reaches theobject) and the shutter closing time Tc may be reset by usingcombinations of the photographing focal lengths, the operatingconditions of the blur prevention device and the kinds of the films.

In the ninth embodiment described above, an exposure time is fixed atthe shutter closing time Tc when a exposure time calculated from objectluminance is longer than the shutter closing time Tc and the shutterclosing time Tc is prolonged when the blur prevention device is operatedand the positive film is used, thereby making it possible to take afavorable photograph by solving the problem that the positive film makesunder-exposure more remarkable.

As understood from the foregoing description, the seventh through ninthembodiments described above provide the vari-focal cameras which arecapable of preventing photographing from being failed due to too muchreliance on the blur prevention device and executing photographing withadequate exposure regardless of selected photographing modes or kinds offilms.

As described above, the present invention of the seventh to the ninthembodiments provides such a vari-focal camera as to prevent anyphotographing failure caused by overestimating the blur preventiondevice and as to take a photograph in proper exposure.

Though each of the embodiments described above is configured on anassumption that the present invention is applied to a lens shuttercamera, the blur prevention device is applicable also to various kindsof cameras such as a single-lens reflex camera and an electronic stillcamera.

Furthermore, though the blur prevention device is configured by havingthe mechanism which prevents blur by displacing the correction lens in adirection perpendicular to the optical axis as shown in FIG. 29, thismechanism is not limitative but the blur prevention device may beconfigured by preventing blur by utilizing a prism which has a variablevertex angle or by electrical processing.

Furthermore, the camera according to the present invention may have aconfiguration which is obtained by combining the embodiments describedabove or technological concepts disclosed by the embodiments.

Further while the present invention has been described with respect towhat is presently considered to be the preferred embodiments, it is tobe understood that the present invention is not limited to the disclosedembodiments. To the contrary, the invention is intended to cover variousmodification and equivalent arrangements included within the spirit andscope of the appended claims. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

Furthermore, the individual components shown in schematic or block formin the drawings are all well-known in the camera arts and their specificconstruction and operation are not critical to the operation or bestmode for carrying out the invention.

Moreover, the camera according to the present invention may beconfigured by combining the embodiments described above or technicalcomponents described therein as occasion demands.

Moreover, a partial or entire configuration of an embodiment of thepresent invention may be configured as an independent camera, combinedwith a camera or used as a component of a camera.

In addition, the present invention is applicable not only various kindsof cameras such as a single-lens reflex camera, a lens shutter cameraand video camera but also optical instruments other than the cameras andother appliances, devices to be applied to the cameras, the opticalinstruments and other appliances, and components composing theseappliances.

The attach claim sheet including parenthesis is for your reference butis not included in the actual application.

What is claimed is:
 1. A camera operable with or without an image blurcorrection device, comprising: exposure time setting means for settingan exposure time in accordance with at least photometry data,sensitivity data of an image recording medium and F number of aphotographic lens; strobe lighting designating means for forciblyilluminating a strobe when the exposure time set by said exposure timesetting means is longer than a first exposure time; shutter closing timesetting means for forcibly terminating an exposure for photographing ata second exposure time regardless of a result of said exposure timesetting means when the exposure time set by said exposure time settingmeans is longer than the second exposure time; and means for selectivelysetting the first exposure time and the second exposure time, whereinwhen the camera is operated without the image blur correction device,the first exposure time and the second exposure time are setsubstantially equal to each other, and when the camera is operated withthe image blur correction device, the first exposure time is setdifferent from the second exposure time.
 2. The camera according toclaim 1, wherein said selective setting means changes a combination ofthe first exposure time and the second exposure time based on an objectdistance.
 3. The camera according to claim 1, wherein said selectivesetting means changes a combination of the first exposure time and thesecond exposure time based on a selected photographing mode other thanselection of whether or not said image blur correction device is to beoperated for photographing.
 4. The camera according to claim 3, wherein,in a first photographing mode, said selective setting means sets asecond exposure time for photographing without the image blur correctiondevice which is longer than that for photographing with the image blurcorrection device, and in a second photographing mode, said selectivesetting means sets a second exposure time for photographing without saidimage blur correction device which is shorter than that forphotographing with the image blur correction device.
 5. The cameraaccording to claim 4, the second exposure time is set longer in thesecond photographing mode than in the first photographing mode.
 6. Thecamera according to claim 5, wherein the second photographing mode is amode for photographing a night view.
 7. The camera according to claim 1,wherein said selective setting means changes a combination of the firstexposure time and the second exposure time based on a focal length. 8.The camera according to claim 1, wherein said shutter closing timesetting means forcibly terminates exposure at a time close to the secondexposure time.
 9. The camera according to claim 1, wherein the imageblur correction device optically corrects image blur.
 10. The cameraaccording to claim 9, wherein said image blur correction device correctsimage blur by deflecting a light bundle.
 11. The camera according toclaim 1, wherein said selective setting means sets the second exposuretime longer than the first exposure time in the case of photographingwith operation of the image blur correction device.